Resource / Attributes is mutating the response.body

[col]

I'd like to be able to access the raw JSON response from a Resource. I've noticed that the Resource class now has an attribute accessor for the response object. Unfortunately there seems to be a bug caused by the Attributes class deleting the '_link' and '_embedded' keys from the representation parameter. When these keys are removed from the representation it mutates the response.body.

I think this can be fixed fairly easily by calling .dup on the response.body when initialising the Resource. Does this sounds like a reasonable solution?

I'm happy to put a pull request together if you agree with the approach.