Update to serde 0.8.0

[dtolnay]

Supersedes #83.

[TyOverby]

Does this serde update include any changes that would change the ordering of bytes produced by bincode?

[dtolnay]

No. There are 3 user-facing changes but all are in deserialization:

• deserialize_str used to not be implemented, meaning it forwarded to deserialize and failed. Now it is implemented to deserialize a &str. This affects only Deserialize types that used to fail and now succeed.
• deserialize_struct_field fails with a better message.
• deserialize_ignored_any fails with a better message.

As an incentive, I suspect you will see a nice performance improvement in serialization for both structs and vectors.

I can put together a test suite this weekend before you release to prove the bytes are the same.

[TyOverby]

Sounds good. I was only asking because I wanted to know if I'd need to bump the version number. However, I'm pretty sure I need to bump the version anyway, simply because it's re-exporting serde which bumped to 0.8.0.

The test suite already makes sure that the rustc-serialize encoding is the same (byte for byte) as the serde encoding, so I'm not super worried.

Thanks for the contribution!

[TyOverby]

Published to crates.io as 0.6.0