Address cargo clippy warnings

[clehner]

The following Cargo clippy warnings and warnings should be addressed.

cargo clippy --workspace @ e6d7e7b

    Checking ssi v0.4.0 (/home/cel/src/ssi)
warning: associated function is never used: `as_struct_mut`
   --> src/eip712.rs:240:8
    |
240 |     fn as_struct_mut(&mut self) -> Option<&mut HashMap<StructName, EIP712Value>> {
    |        ^^^^^^^^^^^^^
    |
    = note: `#[warn(dead_code)]` on by default

warning: unneeded `return` statement
   --> src/did_resolve.rs:892:5
    |
892 |     return (res_meta, result.did_document, result.did_document_metadata);
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return`: `(res_meta, result.did_document, result.did_document_metadata)`
    |
    = note: `#[warn(clippy::needless_return)]` on by default
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return

warning: this expression creates a reference which is immediately dereferenced by the compiler
   --> src/did_resolve.rs:927:51
    |
927 |             percent_encoding::utf8_percent_encode(&did, percent_encoding::CONTROLS).to_string();
    |                                                   ^^^^ help: change this to: `did`
    |
    = note: `#[warn(clippy::needless_borrow)]` on by default
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow

warning: `to_string` applied to a type that implements `Display` in `format!` args
   --> src/did_resolve.rs:953:28
    |
953 |                         err.to_string()
    |                            ^^^^^^^^^^^^ help: remove this
    |
    = note: `#[warn(clippy::to_string_in_format_args)]` on by default
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#to_string_in_format_args

warning: `to_string` applied to a type that implements `Display` in `format!` args
    --> src/did_resolve.rs:1102:28
     |
1102 |                         err.to_string()
     |                            ^^^^^^^^^^^^ help: remove this
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#to_string_in_format_args

warning: this `.into_iter()` call is equivalent to `.iter()` and will not consume the `Vec`
    --> src/eip712.rs:1038:40
     |
1038 |                 let mut values = array.into_iter();
     |                                        ^^^^^^^^^ help: call directly: `iter`
     |
     = note: `#[warn(clippy::into_iter_on_ref)]` on by default
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#into_iter_on_ref

warning: this expression creates a reference which is immediately dereferenced by the compiler
   --> src/jws.rs:175:48
    |
175 |                 let hash = crate::hash::sha256(&data)?;
    |                                                ^^^^^ help: change this to: `data`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow

warning: you seem to be trying to use `match` for destructuring a single pattern. Consider using `if let`
   --> src/revocation.rs:277:9
    |
277 | /         match revocation_list_credential.validate() {
278 | |             Err(e) => {
279 | |                 return result.with_error(format!("Invalid list credential: {}", e));
280 | |             }
281 | |             Ok(()) => {}
282 | |         }
    | |_________^
    |
    = note: `#[warn(clippy::single_match)]` on by default
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_match
help: try this
    |
277 ~         if let Err(e) = revocation_list_credential.validate() {
278 +             return result.with_error(format!("Invalid list credential: {}", e));
279 +         }
    |

warning: `ssi` (lib) generated 8 warnings
    Checking did-onion v0.1.2 (/home/cel/src/ssi/did-onion)
    Checking did-sol v0.0.1 (/home/cel/src/ssi/did-sol)
    Checking did-tz v0.1.2 (/home/cel/src/ssi/did-tezos)
    Checking did-method-key v0.1.3 (/home/cel/src/ssi/did-key)
    Checking did-pkh v0.1.1 (/home/cel/src/ssi/did-pkh)
    Checking did-webkey v0.1.1 (/home/cel/src/ssi/did-webkey)
    Checking did-web v0.1.2 (/home/cel/src/ssi/did-web)
warning: `to_string` applied to a type that implements `Display` in `format!` args
   --> did-onion/src/lib.rs:119:28
    |
119 |                         err.to_string()
    |                            ^^^^^^^^^^^^ help: remove this
    |
    = note: `#[warn(clippy::to_string_in_format_args)]` on by default
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#to_string_in_format_args

warning: `to_string` applied to a type that implements `Display` in `format!` args
   --> did-onion/src/lib.rs:132:28
    |
132 |                         err.to_string()
    |                            ^^^^^^^^^^^^ help: remove this
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#to_string_in_format_args

warning: `to_string` applied to a type that implements `Display` in `format!` args
   --> did-onion/src/lib.rs:149:28
    |
149 |                         err.to_string()
    |                            ^^^^^^^^^^^^ help: remove this
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#to_string_in_format_args

warning: `did-onion` (lib) generated 3 warnings
    Checking did-ion v0.1.0 (/home/cel/src/ssi/did-ion)
warning: `to_string` applied to a type that implements `Display` in `format!` args
   --> did-webkey/src/lib.rs:242:28
    |
242 |                         err.to_string()
    |                            ^^^^^^^^^^^^ help: remove this
    |
    = note: `#[warn(clippy::to_string_in_format_args)]` on by default
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#to_string_in_format_args

    Checking did-ethr v0.1.1 (/home/cel/src/ssi/did-ethr)
warning: `to_string` applied to a type that implements `Display` in `format!` args
   --> did-webkey/src/lib.rs:259:28
    |
259 |                         err.to_string()
    |                            ^^^^^^^^^^^^ help: remove this
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#to_string_in_format_args

    Checking ssi-vc-test v0.1.0 (/home/cel/src/ssi/vc-test)
warning: `did-webkey` (lib) generated 2 warnings
warning: `to_string` applied to a type that implements `Display` in `format!` args
   --> did-web/src/lib.rs:118:28
    |
118 |                         err.to_string()
    |                            ^^^^^^^^^^^^ help: remove this
    |
    = note: `#[warn(clippy::to_string_in_format_args)]` on by default
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#to_string_in_format_args

warning: `to_string` applied to a type that implements `Display` in `format!` args
   --> did-web/src/lib.rs:135:28
    |
135 |                         err.to_string()
    |                            ^^^^^^^^^^^^ help: remove this
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#to_string_in_format_args

warning: `did-web` (lib) generated 2 warnings
warning: this `impl` can be derived
  --> did-tezos/src/lib.rs:36:1
   |
36 | / impl Default for DIDTz {
37 | |     fn default() -> Self {
38 | |         Self { tzkt_url: None }
39 | |     }
40 | | }
   | |_^
   |
   = note: `#[warn(clippy::derivable_impls)]` on by default
   = help: try annotating `DIDTz` with `#[derive(Default)]`
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#derivable_impls

warning: `to_string` applied to a type that implements `Display` in `format!` args
   --> did-tezos/src/lib.rs:428:28
    |
428 |                     address.to_string()
    |                            ^^^^^^^^^^^^ help: remove this
    |
    = note: `#[warn(clippy::to_string_in_format_args)]` on by default
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#to_string_in_format_args

warning: `did-tz` (lib) generated 2 warnings
    Checking ssi-did-test v0.1.0 (/home/cel/src/ssi/did-test)
warning: unused imports: `StatusCode`, `header`
 --> did-ion/src/sidetree.rs:5:15
  |
5 | use reqwest::{header, Client, StatusCode};
  |               ^^^^^^          ^^^^^^^^^^
  |
  = note: `#[warn(unused_imports)]` on by default

warning: field is never read: `type`
   --> did-ion/src/sidetree.rs:517:5
    |
517 |     r#type: Option<String>,
    |     ^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `#[warn(dead_code)]` on by default
note: `PartiallyVerifiedCreateOperation` has derived impls for the traits `Clone` and `Debug`, but these are intentionally ignored during dead code analysis
   --> did-ion/src/sidetree.rs:514:10
    |
514 | #[derive(Debug, Clone)]
    |          ^^^^^  ^^^^^
    = note: this warning originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)

warning: field is never read: `anchor_origin`
   --> did-ion/src/sidetree.rs:519:5
    |
519 |     anchor_origin: Option<String>,
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
note: `PartiallyVerifiedCreateOperation` has derived impls for the traits `Clone` and `Debug`, but these are intentionally ignored during dead code analysis
   --> did-ion/src/sidetree.rs:514:10
    |
514 | #[derive(Debug, Clone)]
    |          ^^^^^  ^^^^^
    = note: this warning originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)

warning: field is never read: `signed_anchor_origin`
   --> did-ion/src/sidetree.rs:542:5
    |
542 |     signed_anchor_origin: Option<String>,
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
note: `PartiallyVerifiedRecoverOperation` has derived impls for the traits `Clone` and `Debug`, but these are intentionally ignored during dead code analysis
   --> did-ion/src/sidetree.rs:536:10
    |
536 | #[derive(Debug, Clone)]
    |          ^^^^^  ^^^^^
    = note: this warning originates in the derive macro `Debug` (in Nightly builds, run with -Z macro-backtrace for more info)

warning: this expression creates a reference which is immediately dereferenced by the compiler
   --> did-ion/src/sidetree.rs:318:54
    |
318 |         let update_reveal_value = Self::reveal_value(&canonicalized_update_pk.as_bytes());
    |                                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: change this to: `canonicalized_update_pk.as_bytes()`
    |
    = note: `#[warn(clippy::needless_borrow)]` on by default
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow

warning: this expression creates a reference which is immediately dereferenced by the compiler
   --> did-ion/src/sidetree.rs:326:37
    |
326 |             Self::commitment_scheme(&new_update_pk).context("Generate new update commitment")?;
    |                                     ^^^^^^^^^^^^^^ help: change this to: `new_update_pk`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow

warning: this expression creates a reference which is immediately dereferenced by the compiler
   --> did-ion/src/sidetree.rs:375:55
    |
375 |         let recover_reveal_value = Self::reveal_value(&canonicalized_recovery_pk.as_bytes());
    |                                                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: change this to: `canonicalized_recovery_pk.as_bytes()`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow

warning: this expression creates a reference which is immediately dereferenced by the compiler
   --> did-ion/src/sidetree.rs:377:37
    |
377 |             Self::commitment_scheme(&new_update_pk).context("Generate new update commitment")?;
    |                                     ^^^^^^^^^^^^^^ help: change this to: `new_update_pk`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow

warning: this expression creates a reference which is immediately dereferenced by the compiler
   --> did-ion/src/sidetree.rs:379:37
    |
379 |             Self::commitment_scheme(&new_recovery_pk).context("Generate new update commitment")?;
    |                                     ^^^^^^^^^^^^^^^^ help: change this to: `new_recovery_pk`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow

warning: this expression creates a reference which is immediately dereferenced by the compiler
   --> did-ion/src/sidetree.rs:451:55
    |
451 |         let recover_reveal_value = Self::reveal_value(&canonicalized_recovery_pk.as_bytes());
    |                                                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: change this to: `canonicalized_recovery_pk.as_bytes()`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow

warning: large size difference between variants
   --> did-test/src/main.rs:109:5
    |
109 | /     Resolve {
110 | |         did_document: Option<Document>,
111 | |         did_resolution_metadata: ResolutionMetadata,
112 | |         did_document_metadata: DocumentMetadata,
113 | |     },
    | |_____^ this variant is 592 bytes
    |
    = note: `#[warn(clippy::large_enum_variant)]` on by default
note: and the second-largest variant is 216 bytes:
   --> did-test/src/main.rs:121:5
    |
121 | /     Dereference {
122 | |         dereferencing_metadata: DereferencingMetadata,
123 | |         content_stream: String,
124 | |         content_metadata: ContentMetadata,
125 | |     },
    | |_____^
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#large_enum_variant
help: consider boxing the large fields to reduce the total size of the enum
    |
110 |         did_document: Box<Option<Document>>,
    |                       ~~~~~~~~~~~~~~~~~~~~~

warning: this expression creates a reference which is immediately dereferenced by the compiler
   --> did-ion/src/sidetree.rs:625:49
    |
625 |     let computed_reveal_value = S::reveal_value(&commitment_value);
    |                                                 ^^^^^^^^^^^^^^^^^ help: change this to: `commitment_value`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow

warning: this expression creates a reference which is immediately dereferenced by the compiler
   --> did-ion/src/sidetree.rs:628:30
    |
628 |         S::commitment_scheme(&pk).context("Unable to compute public key commitment")?;
    |                              ^^^ help: change this to: `pk`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow

warning: this expression creates a reference which is immediately dereferenced by the compiler
   --> did-ion/src/sidetree.rs:673:21
    |
673 |                     &update_commitment,
    |                     ^^^^^^^^^^^^^^^^^^ help: change this to: `update_commitment`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow

warning: this expression creates a reference which is immediately dereferenced by the compiler
   --> did-ion/src/sidetree.rs:683:21
    |
683 |                     &recovery_commitment,
    |                     ^^^^^^^^^^^^^^^^^^^^ help: change this to: `recovery_commitment`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow

warning: this expression creates a reference which is immediately dereferenced by the compiler
   --> did-ion/src/sidetree.rs:703:21
    |
703 |                     &recovery_commitment,
    |                     ^^^^^^^^^^^^^^^^^^^^ help: change this to: `recovery_commitment`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow

warning: for loop over a single element
   --> did-test/src/main.rs:284:5
    |
284 | /     for did in &["did:onion:fscst5exmlmr262byztwz4kzhggjlzumvc2ndvgytzoucr2tkgxf7mid"] {
285 | |         let did_vector = did_method_vector(&resolver, did).await;
286 | |         did_vectors.insert(did.to_string(), did_vector);
287 | |     }
    | |_____^
    |
    = note: `#[warn(clippy::single_element_loop)]` on by default
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_element_loop
help: try
    |
284 ~     {
285 +         let did = &"did:onion:fscst5exmlmr262byztwz4kzhggjlzumvc2ndvgytzoucr2tkgxf7mid";
286 +         let did_vector = did_method_vector(&resolver, did).await;
287 +         did_vectors.insert(did.to_string(), did_vector);
288 +     }
    |

warning: for loop over a single element
   --> did-test/src/main.rs:341:5
    |
341 | /     for did in &["did:webkey:ssh:demo.spruceid.com:2021:07:14:keys"] {
342 | |         let did_vector = did_method_vector(&resolver, did).await;
343 | |         did_vectors.insert(did.to_string(), did_vector);
344 | |     }
    | |_____^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_element_loop
help: try
    |
341 ~     {
342 +         let did = &"did:webkey:ssh:demo.spruceid.com:2021:07:14:keys";
343 +         let did_vector = did_method_vector(&resolver, did).await;
344 +         did_vectors.insert(did.to_string(), did_vector);
345 +     }
    |

warning: for loop over a single element
   --> did-test/src/main.rs:511:5
    |
511 | /     for did in &["did:key:z6MkpTHR8VNsBxYAAWHut2Geadd9jSwuBV8xRoAnwWsdvktH"] {
512 | |         report
513 | |             .resolve_representation(
514 | |                 &did_method_key::DIDKey,
...   |
518 | |             .await;
519 | |     }
    | |_____^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_element_loop
help: try
    |
511 ~     {
512 +         let did = &"did:key:z6MkpTHR8VNsBxYAAWHut2Geadd9jSwuBV8xRoAnwWsdvktH";
513 +         report
514 +             .resolve_representation(
515 +                 &did_method_key::DIDKey,
516 +                 did,
  ...

warning: for loop over a single element
   --> did-test/src/main.rs:543:5
    |
543 | /     for did in &["did:web:identity.foundation"] {
544 | |         report
545 | |             .resolve_representation(&did_web::DIDWeb, did, &ResolutionInputMetadata::default())
546 | |             .await;
547 | |     }
    | |_____^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_element_loop
help: try
    |
543 ~     {
544 +         let did = &"did:web:identity.foundation";
545 +         report
546 +             .resolve_representation(&did_web::DIDWeb, did, &ResolutionInputMetadata::default())
547 +             .await;
548 +     }
    |

warning: for loop over a single element
   --> did-test/src/main.rs:574:5
    |
574 | /     for did in &["did:tz:tz1YwA1FwpgLtc1G8DKbbZ6e6PTb1dQMRn5x"] {
575 | |         report
576 | |             .resolve_representation(&did_tz, did, &ResolutionInputMetadata::default())
577 | |             .await;
578 | |     }
    | |_____^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_element_loop
help: try
    |
574 ~     {
575 +         let did = &"did:tz:tz1YwA1FwpgLtc1G8DKbbZ6e6PTb1dQMRn5x";
576 +         report
577 +             .resolve_representation(&did_tz, did, &ResolutionInputMetadata::default())
578 +             .await;
579 +     }
    |

warning: for loop over a single element
   --> did-test/src/main.rs:594:5
    |
594 | /     for did in &["did:onion:fscst5exmlmr262byztwz4kzhggjlzumvc2ndvgytzoucr2tkgxf7mid"] {
595 | |         report
596 | |             .resolve(&resolver, did, &ResolutionInputMetadata::default())
597 | |             .await;
598 | |     }
    | |_____^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_element_loop
help: try
    |
594 ~     {
595 +         let did = &"did:onion:fscst5exmlmr262byztwz4kzhggjlzumvc2ndvgytzoucr2tkgxf7mid";
596 +         report
597 +             .resolve(&resolver, did, &ResolutionInputMetadata::default())
598 +             .await;
599 +     }
    |

warning: for loop over a single element
   --> did-test/src/main.rs:600:5
    |
600 | /     for did in &["did:onion:fscst5exmlmr262byztwz4kzhggjlzumvc2ndvgytzoucr2tkgxf7mid"] {
601 | |         report
602 | |             .resolve_representation(&resolver, did, &ResolutionInputMetadata::default())
603 | |             .await;
604 | |     }
    | |_____^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_element_loop
help: try
    |
600 ~     {
601 +         let did = &"did:onion:fscst5exmlmr262byztwz4kzhggjlzumvc2ndvgytzoucr2tkgxf7mid";
602 +         report
603 +             .resolve_representation(&resolver, did, &ResolutionInputMetadata::default())
604 +             .await;
605 +     }
    |

warning: for loop over a single element
   --> did-test/src/main.rs:620:5
    |
620 | /     for did in &["did:pkh:doge:DH5yaieqoZN36fDVciNyRueRGvGLR3mr7L"] {
621 | |         report
622 | |             .resolve(&resolver, did, &ResolutionInputMetadata::default())
623 | |             .await;
624 | |     }
    | |_____^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_element_loop
help: try
    |
620 ~     {
621 +         let did = &"did:pkh:doge:DH5yaieqoZN36fDVciNyRueRGvGLR3mr7L";
622 +         report
623 +             .resolve(&resolver, did, &ResolutionInputMetadata::default())
624 +             .await;
625 +     }
    |

warning: for loop over a single element
   --> did-test/src/main.rs:626:5
    |
626 | /     for did in &["did:pkh:doge:DH5yaieqoZN36fDVciNyRueRGvGLR3mr7L"] {
627 | |         report
628 | |             .resolve_representation(&resolver, did, &ResolutionInputMetadata::default())
629 | |             .await;
630 | |     }
    | |_____^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_element_loop
help: try
    |
626 ~     {
627 +         let did = &"did:pkh:doge:DH5yaieqoZN36fDVciNyRueRGvGLR3mr7L";
628 +         report
629 +             .resolve_representation(&resolver, did, &ResolutionInputMetadata::default())
630 +             .await;
631 +     }
    |

warning: for loop over a single element
   --> did-test/src/main.rs:646:5
    |
646 | /     for did in &["did:webkey:ssh:demo.spruceid.com:2021:07:14:keys"] {
647 | |         report
648 | |             .resolve(&resolver, did, &ResolutionInputMetadata::default())
649 | |             .await;
650 | |     }
    | |_____^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_element_loop
help: try
    |
646 ~     {
647 +         let did = &"did:webkey:ssh:demo.spruceid.com:2021:07:14:keys";
648 +         report
649 +             .resolve(&resolver, did, &ResolutionInputMetadata::default())
650 +             .await;
651 +     }
    |

warning: for loop over a single element
   --> did-test/src/main.rs:652:5
    |
652 | /     for did in &["did:webkey:ssh:demo.spruceid.com:2021:07:14:keys"] {
653 | |         report
654 | |             .resolve_representation(&resolver, did, &ResolutionInputMetadata::default())
655 | |             .await;
656 | |     }
    | |_____^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_element_loop
help: try
    |
652 ~     {
653 +         let did = &"did:webkey:ssh:demo.spruceid.com:2021:07:14:keys";
654 +         report
655 +             .resolve_representation(&resolver, did, &ResolutionInputMetadata::default())
656 +             .await;
657 +     }
    |

warning: `ssi-did-test` (bin "ssi-did-test") generated 12 warnings
warning: this expression creates a reference which is immediately dereferenced by the compiler
    --> did-ion/src/sidetree.rs:1412:53
     |
1412 |             .map(|url| HTTPSidetreeDIDResolver::new(&url));
     |                                                     ^^^^ help: change this to: `url`
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow

error: this loop never actually loops
    --> did-ion/src/sidetree.rs:1596:9
     |
1596 | /         for opt in options.keys() {
1597 | |             return Err(DIDMethodError::OptionNotSupported {
1598 | |                 operation: "create",
1599 | |                 option: opt.clone(),
1600 | |             });
1601 | |         }
     | |_________^
     |
     = note: `#[deny(clippy::never_loop)]` on by default
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#never_loop
help: if you need the first element of the iterator, try writing
     |
1596 |         if let Some(opt) = options.keys().next() {
     |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

error: this loop never actually loops
    --> did-ion/src/sidetree.rs:1676:9
     |
1676 | /         for opt in options.keys() {
1677 | |             return Err(DIDMethodError::OptionNotSupported {
1678 | |                 operation: "update",
1679 | |                 option: opt.clone(),
1680 | |             });
1681 | |         }
     | |_________^
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#never_loop
help: if you need the first element of the iterator, try writing
     |
1676 |         if let Some(opt) = options.keys().next() {
     |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

error: this loop never actually loops
    --> did-ion/src/sidetree.rs:1708:9
     |
1708 | /         for opt in options.keys() {
1709 | |             return Err(DIDMethodError::OptionNotSupported {
1710 | |                 operation: "recover",
1711 | |                 option: opt.clone(),
1712 | |             });
1713 | |         }
     | |_________^
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#never_loop
help: if you need the first element of the iterator, try writing
     |
1708 |         if let Some(opt) = options.keys().next() {
     |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

error: this loop never actually loops
    --> did-ion/src/sidetree.rs:1739:9
     |
1739 | /         for opt in options.keys() {
1740 | |             return Err(DIDMethodError::OptionNotSupported {
1741 | |                 operation: "deactivate",
1742 | |                 option: opt.clone(),
1743 | |             });
1744 | |         }
     | |_________^
     |
     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#never_loop
help: if you need the first element of the iterator, try writing
     |
1739 |         if let Some(opt) = options.keys().next() {
     |         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

warning: this expression creates a reference which is immediately dereferenced by the compiler
  --> did-ion/src/lib.rs:20:26
   |
20 |         if !is_secp256k1(&key) {
   |                          ^^^^ help: change this to: `key`
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow

warning: `did-ion` (lib) generated 17 warnings
error: could not compile `did-ion` due to 4 previous errors; 17 warnings emitted

[chunningham]

I believe this is closed by #467