Update to use widop/http-adapter version 1.1+

This change reflects the change in widop/http-adapter which happened in version 1.1.
Before this version, $response was a string (the HTTP response). Now the response is wrapped in a class,  and the old content is extracted with method getBody().
Sorry but can you just add `~1.1`? Basically, it will allow to install `1.x` starting from the `1.1` version and will forbid to install the `1.0.x` versions. And if you can squash all your commits in a single one too otherwise I will need to do it by myself. Thx!