Remove the tripleo-test-cloud provider

Temporarily stop using this provider as its causing various problems,
the load on CI has been reduced to allow R2 to be able to handle it
solo. Once we redeploy and gain some confidence in this region we
will be adding it back in. Setting max-servers to 0 will allow nodepool
to gracefully cleanup nodes.

Change-Id: Ib16dbef47b74bb027d47c60b50448d51c0110ca3
Merge "Remove the tripleo-test-cloud provider"