[WIP] Refactoring to use ivory-http-adapter

I have started to rewrite the client interface to use egeloen/ivory-http-adapter. The reason for this is that people could pick there own client to work with this library. One other reason is that it follows the PSR-7 specs and it allows us to fix my orinonal proposal to add the Response code #144. 

All the test work as of now but I still need tot test if it really stil works with some current providers. But I would like to hear feedback.