Revert "Extract projects.yaml loader into a module."

This was not ready to be merged.

This reverts commit 8b9f93f67ad43e0ac8dd95e02f8269f6d7cae912

Change-Id: Icef953ba61959b6b2e7aa18731eb7b953379195b
Reviewed-on: https://review.openstack.org/26104
Approved: Jeremy Stanley <fungi@yuggoth.org>
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Tested-by: Jenkins