Allow deriving traits on the Error

[Yamakaky]

Possible syntax:

error_chain! {
  derive { Eq, PartialEq }
  ...
}

We may have to add a trait which the chained errors would have to implement.

[TedDriggs]

Should this be done as "attrs" or something that would also allow passing attributes for proc macro crates like serde_derive?

[kpcyrd]

Any news? Ran into this problem while I was trying to use pseudo :)

[ivanovaleksey]

Hello, are there any updates in this?

[lneicelis]

Any updates?