Smart body parsing based on Content-Type

[techniq]

Instead of defaulting to json for body parsing, it would be better if we read the response's Content-Type header and parsed accordingly. This would also better handle when the endpoint changes types (ex. some frameworks will return a HTML debug page when a 500 is thrown, which breaks when we expect an endpoint to return JSON).

After a quick look around, it appears fetch-parse has a good start on the mapping between Content-Type and parsers.

Probably look at using one of the following to parse the header / mime type, as it can be fairly involved to cover all cases defined by the spec.

• https://github.com/jsdom/whatwg-mimetype
• https://github.com/jshttp/content-type
• https://github.com/hapijs/content

Lastly, it would be nice to support passing a function to as to allow the user to perform the body parsing mapping themselves (might be needed to determine whether they need blob or arrayBuffer.