Use the test env JSON to detect remote VM hosts.
Use the test env JSON to detect remote VM hosts.

This permits devtest_seed to automatically do the right thing in a
TripleO-CI environment. Well, nearly - we still need to fixup some of
the post boot steps, but we should at least have a seed booting from
this.

Change-Id: I1fedc9e41ba2eec96bd21ec618ff48a678a383ce

rdo-management/tripleo,rdo-management/tripleo