Add base64 conversion traits

[xd009642]

I'll add some tests and more doc comments later just wanted to make sure this was in the ballpark of what was expected.

Fixes #54

[jtescher]

@xd009642 yeah this direction looks good, maybe have this be an optional feature like serde is currently? Nice to keep the dependency list short for people who don't need all the features.

[xd009642]

I can do that once I finish work today 👍 base64 is a small dependency though with no subdependencies so should I at least make it a default feature?

[xd009642]

also I signed the cla/linuxfoundation so I guess that will switch to pass on the next commit I push?

[jtescher]

Sounds good! Normally I think default feature could make sense, however the binary format is in flux / may be removed so probably best to have this be opt-in for now.

[xd009642]

@jtescher I've moved base64 to it's own feature and also decided to do a blanket implementation for anything that implements BinaryFormat filled in the to_base64 test replicating the binary format to_bytes test. Just need to fill in some more tests for the from_base64

[xd009642]

I signed it

[jtescher]

This looks good! do you want to also export this in the api module to make it a little more ergonomic for consumers? nice to be able to use at that level: use api::Base64Format

[xd009642]

Done 😄

[jtescher]

Great, thanks!