Remove tripleo cross-testing with oslotest

This was added before we realized a separate cross-test job for
every project that uses oslotest was not going to be practical. It
also seems to have issues with the stable branches of the tripleo
projects, so we're just going to remove them for now.  Once we've
come up with a cross-testing strategy for Oslo we will add these
projects back in to the testing matrix.

Change-Id: I5679a135ab4925d9db8471397d052e53a5c93b4b
Merge "Remove tripleo cross-testing with oslotest"