Allow using any implementation of PSR-7

[shadowhand]

Geocoder claims to support PSR-7 but requires a concrete implementation of PSR-7 in egeloen/http-adapter which in turn requires zendframework/zend-diactoros. This is not how PSR-7 is supposed to be used. The only requirement for PSR-7 compatible packages is psr/http-message and all request/response type hints should be against those interfaces.

This currently prevents me from using this package with Guzzle or any other implementation of PSR-7. If I were to install this package right now, I would have both Guzzle and Diactoros installed, implementing the exact same PSR-7 interfaces, which is exactly the situation that PSR-7 is supposed to allow us to avoid.

[willdurand]

This is going to change in the near future. We will adopt HTTPlug

[willdurand]

poke @egeloen

[egeloen]

I know :) Ivory http adapter is strongly coupled to Diactoros and will not be decoupled from it. Anyway, Httplug is and moving to it should not be so difficult. I will try to provide a PoC this week-end.

[bazo]

what's new regarding this issue?
composer now warns that egeloen/http-adapter is deprecated

[willdurand]

See #512