"egeloen/http-adapter" deprecated

[dereuromark]

Composer message:

Package egeloen/http-adapter is abandoned, you should avoid using it. Use php-http/httplug instead.

You should remove "egeloen/http-adapter" from require, and instead move it to require-dev.
This suffices for testing but allows people to use other not deprecated packages instead.
In general it is always a good idea to not directly include those proposed dependencies in require, but keep them in require-dev or suggest.

[drupol]

I'm working on a GuzzleHttpAdapter in the Drupal module so I can use Guzzle directly.

[willdurand]

Yep. Duplicate of #480. Should be fixed by #487