Make `de::Error` `Eq` in addition to current `PartialEq` (#330)
Make `de::Error` `Eq` in addition to current `PartialEq` (#330)

Not sure why this wasn't implemented before, since `ser::Error` has implemented `PartialEq` and `Eq` as of PR #144.
alexcrichton/toml-rs,GuillaumeGomez/toml-rs