init: do not silence migration errors
install: silence stdout of git clone operations
init: use linkage to fetch additional mysql access parameters
init: added support for centurylink/mysql and orchardup/mysql images
init: use linkage to fetch additional postgresql access parameters
init: added support for orchardup/postgresql image
init: added support for paintedfox/postgresql image
dockerfile: switch back to sameersbn/ubuntu:14.04 image

There are some compatibility issues with between gitlab-ci 5.0.1 and ruby 2.1.3

References:
  - https://github.com/gitlabhq/gitlab-ci/issues/480
  - https://github.com/gitlabhq/gitlab-ci/commit/3b4e93e4dfe17bf994eb2fc711442c3b8c90c8dc