Found that the id from the ObjectAttribute dit not point to the id of the merge request. In my cases the iid has the number of the merge request.

This commit adds the iid to the ObjectAttribute and changes the GitLabMergerCause description to us this instead of the id.
Cleanup: Removed logging used for debugging
Added a config option to let the user select whatever we want the plugin to trigger a rebuild of open merge requests when receiving a push event from GitLab
Merge remote-tracking branch 'parent/develop' into check_merge_request_on_push
Merge pull request #35 from kasper-f/check_merge_request_on_push

Check merge request on push