Error: custom reponse error message

[fundon]

Examples:

• https://zeit.co/docs/api#api-basics/errors

  Struct:

  {
  "error": {
    "code": "forbidden",
    "message": "Not authorized"
  }
  }

• https://github.com/graphql/graphql-spec/blob/master/spec/Section%207%20--%20Response.md

• https://www.apollographql.com/docs/apollo-server/data/errors/

  Struct

  {
  "errors": [
    { "message": "" }
  ]
  }

[fundon]

https://github.com/rust-lang-nursery/failure

[fundon]

https://github.com/dtolnay/anyhow

[fundon]

Landed in https://github.com/trek-rs/trek/commit/7137b9ca03b956b8a46a60bb48e1742277f28827.