Add -tripleo pipelines.

The experimental-tripleo pipeline is to enable building out tripleo
tests against other projects in advance of the second region coming
online.

The check-tripleo pipeline ensures that in the event of a tripleo
cloud failure the main check queue won't appear to backlog, making
analysis of devstack-gate check health easier.

Change-Id: I93045879c508defd4f1f86979fb42da79bd29fad
Merge "Add -tripleo pipelines."