Make adapters PSR-7 compliant about httplug

[sagikazarmark]

It is definitely relevant as it contains some changes that needs to be backported. Also, the separation itself is step one to remove the internal request thing from the adapters.

[ddeboer]

Okay, so let’s first get the internal_separation branches merged, and then continue with cleaning up the adapter interfaces.

[sagikazarmark]

Yeah.

[sagikazarmark]

I am planning to merge those branches by the end of the week.

[ddeboer]

Cool! Let me know when you have done that. I’ll write a PR after that to clean up the Adapter interfaces with the Guzzle 6 adapter as a (very simple) testcase.