Update postgresql to 9.5.x
Use postgresql latest version (9.5.1 as of now) for building omnibus-gitlab because .gitlab-ci.yml on gitlab-org/gitlab-ce (as well as gitlab-ee) specifies only the latest version of postgres to test code of GitLab.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Use postgresql latest version (9.5.1 as of now) for building omnibus-gitlab because .gitlab-ci.yml on gitlab-org/gitlab-ce (as well as gitlab-ee) specifies only the latest version of postgres to test code of GitLab.