Update Ruby version to 2.3 in Requirements
According to the GitLab 8.11 release notes, Ruby 2.3 is now supported and recommended. Update the documentation accordingly.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
According to the GitLab 8.11 release notes, Ruby 2.3 is now supported and recommended. Update the documentation accordingly.