1.Use opendev.org instead of git.openstack.org.
2.Use review.opendev.org instead of review.openstack.org.

You can see the discussion below:
http://lists.openstack.org/pipermail/openstack-discuss/2019-March/003603.html

Change-Id: Ice4509204df788a1a44a06fb89fb44cfe6b54b94

Change-Id: Ib0ef21f23a8b54d43278454bbd6ed6bde419c5f0

Github is just a mirror of the OpenStack git-repo.
Changed from Github to OpenStack git url wherever possible.

Change-Id: I7941ef86967de4efe7f23ff9fb11ec86c793901e

Change-Id: Ie2f5a3b8e239cae13909cf70f8be44b05b19d431

Previously, a spec did not exist to define how Kolla will support
highly available OpenStack services.

Change-Id: I8fcc60f26d2cb98179be6b520c13abb22a372ecf