Bump strum from 0.19.5 to 0.21.0

[dependabot]

Bumps strum from 0.19.5 to 0.21.0.

Changelog

Sourced from strum's changelog.

0.21.0

• Replace std:: with core:: to support no-std projects. #145

• Breaking Changes

  • MSRV is updated to 1.32 because heck does not work in 1.31.1 anymore. Rust 1.32 came out Jan 2019 so hopefully teams have moved to an equal or newer version.
  • #149 Remove the "rename" feature. In Rust 2018, macros should be imported using a qualified path to avoid collisions. strum_macros::EnumString rather than using the "Rename" feature to avoid collisions.
  • #160 enum messages: Make the returned values all 'static
    • It is unlikely this will break anyone, but the new signature for functions generated by EnumMessage is fn get_message(&self) -> Option<&'static str>.

• Added support for ascii_case_insensitive string comparisons. #157 This feature allows FromString impls to match strings that differ in case from the expected variant.

0.20.0

• Refactors to do better error handling. Thanks @​jplatte for these changes

  • #133
  • #134
  • #135

• Adding vis(scope) to EnumDiscriminants. #137

  • This feature works best with versions of rust >= 1.34 due to a rustc parsing error in earlier versions.
  • Earlier versions can still use vis(r#pub)

• These changes should not be breaking, but the amount of code modified was significant.

• FYI about #122. The macro renames feature will be removed in early 2021. This feature was only necessary in rust 2015 because macros didn't support qualified imports so macro names could collide between crates.

Commits

• See full diff in compare view

Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting @dependabot rebase.

---

Dependabot commands and options

You can trigger Dependabot actions by commenting on this PR:

• @dependabot rebase will rebase this PR
• @dependabot recreate will recreate this PR, overwriting any edits that have been made to it
• @dependabot merge will merge this PR after your CI passes on it
• @dependabot squash and merge will squash and merge this PR after your CI passes on it
• @dependabot cancel merge will cancel a previously requested merge and block automerging
• @dependabot reopen will reopen this PR if it is closed
• @dependabot close will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually
• @dependabot ignore this major version will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this minor version will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself)
• @dependabot ignore this dependency will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)

[dependabot]

Looks like strum is up-to-date now, so this is no longer needed.