Update documentation to use Ruby 2.3.1
GitLab is using Ruby 2.3.1 now on master, I figure the documentation should also be updated.
See https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4948
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
GitLab is using Ruby 2.3.1 now on master, I figure the documentation should also be updated.
See https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4948