Fix dependency issues

[trevor-crypto]

1. Reorganize dependencies and remove requirements ("=") on wasm-bindgen
   and js-sys, due to conflicts that can occur when using this crate.
2. Replace wasm-bindgen's "serde-serialize" feature with
   serde-wasm-bindgen due to cyclical dependency issue.

Relates to:
tkaitchuck/aHash#95
rustwasm/wasm-bindgen#3031

[lisicky]

/check

[lisicky]

@trevor-crypto perfect PR, thanks!

[trevor-crypto]

@lisicky thank you for reviewing. It appears that the failing check is warning that a pub(crate) function is unused. It is used only in a test. Should I add the #[cfg(test)] on it, or just leave it?

[lisicky]

Thanks @trevor-crypto :) This is our problem, don't worry we will fix it.

[vsubhuman]

Thank you, @trevor-crypto !