The ct_eq_bytes method produces an invalid Choice

[rot256]

Feel free to just pick the fix commit, in case you don't want the regression test.

The test fails with:

---- tests::ct_eq_bytes_produces_valid_choice stdout ----

thread 'tests::ct_eq_bytes_produces_valid_choice' panicked at /Users/rot256/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/subtle-2.6.1/src/lib.rs:239:9:
assertion failed: (input == 0u8) | (input == 1u8)
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

[tarcieri]

That entire function looks like it could be replace with the ConstantTimeEq impl for [T]

[rot256]

Yea, that's the better idea.

[rot256]

Got rid of fn ct_verify(&self, a: &[u16], b: &[u16]) -> Choice { as well.