misaligned pointer dereference in test append

[riking]

https://asan.saethlin.dev/ub?crate=tripcode&version=0.2.1

test tests::append ... thread 'tests::append' panicked at src/lib.rs:665:30:
misaligned pointer dereference: address must be a multiple of 0x8 but is 0x7f77ba3fce42
stack backtrace:
   0: rust_begin_unwind
             at /root/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/std/src/panicking.rs:597:5
   1: core::panicking::panic_nounwind_fmt
             at /root/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/panicking.rs:106:14
   2: core::panicking::panic_misaligned_pointer_dereference
             at /root/.rustup/toolchains/nightly-x86_64-unknown-linux-gnu/lib/rustlib/src/rust/library/core/src/panicking.rs:203:5
   3: <tripcode::Sc15 as tripcode::TripcodeGenerator>::hash::{{closure}}
             at ./src/lib.rs:665:30
   4: tripcode::sha1_internal
             at ./src/lib.rs:580:5
   5: <tripcode::Sc15 as tripcode::TripcodeGenerator>::hash
             at ./src/lib.rs:656:9
   6: <tripcode::ScKatakana as tripcode::TripcodeGenerator>::hash
             at ./src/lib.rs:677:24
   7: tripcode::TripcodeGenerator::append
             at ./src/lib.rs:279:9
   8: tripcode::tests::append
             at ./src/lib.rs:829:9
   9: tripcode::tests::append::{{closure}}
             at ./src/lib.rs:820:16

You may want to consider the ring crate if you are looking for a SHA1 implementation.