Some improvements

* Added contributors list to `composer.json` (linked to github contributors graph)
* Improved Behat context
* Fixed/Cleaned/Tested configure options handling
* add `--default` option to `install` command
I tend to think that using --no-interaction could be a good thing. We also need option for default (or custom values) without any interactions, for snapshots builds and co. So we have to find something that could work in all cases. Not sure the --no-interaction is the right one but with other options it could do it. thoughts?