Improved error messages for invalid field and invalid type errors

[jaggederest]

I ran into these errors and found them inscrutable, so I thought I would update the response strings with some suggestions about how to fix them.

We could extend this to other errors, as well, but I wanted to get feedback before I forged off into the wilderness too far.

Thanks, all feedback appreciated!

Justin

[lgebhardt]

@jaggederest That sort of expanded error message seems good to me. Don't forget we need to change it in locales/en.yml as well.

[jaggederest]

Will do, thanks for the feedback

[lgebhardt]

@jaggederest I'm not sure if you've seen it, but one of the existing tests is failing due to the expanded error message:

Failure:
JSONAPIRequestTest#test_parse_dasherized_with_underscored_fields [/home/travis/build/cerebris/jsonapi-resources/test/unit/jsonapi_request/jsonapi_request_test.rb:141]:
--- expected
+++ actual
@@ -1 +1 @@
-"iso_currency is not a valid field for expense-entries."
+"iso_currency is not a valid field for expense-entries. Consider checking the spelling of the field name."
bin/rails test unit/jsonapi_request/jsonapi_request_test.rb:121