Provide integration with WebApiExtension

[fesor]

For those who use web-api-extension it's not so easy to use json_spec. @tyx provided his proof-of-concept to integrate WebApiContext with json context: tyx/WebApiExtension@58d832a but i don't like the idea of extending context to use it with another.

Solution: use wrapped Guzzle/Client to get last response.

[fabioginzel]

How its work?

[fesor]

Currently only mink support comes out of the box. Currently is just impossible to do this with web-api-extension since we don't have access to response.

I closed this issue only because i don't use web-api-extension. If you need a way for Guzzle transparent support i will reopen in.

One possible solution is to wrap client and remember it's responses from this proxy object... If you really need this, then i can make one in a next week (also welcome for your PRs 😉 ).

[fabioginzel]

thank you, I am very grateful