Making nigthly test definition editable by FreeIPA's contributors

Now the test definition of nightly tests will be on freeipa repo. The
definition that's used on every PR (previously as .freeipa-pr-ci.yaml)
is in ipatests/prci_definitions/gating and the .freeipa-pr-ci.yaml file
is just a symlink to the real file.

In the same dir there is also nightly_master and nightly_rawhide, both
to be used in nightly tests.

Divided test_topology.py into 3 subtests.

Bumped vagrant template to version 0.1.6

This PR is the result of discussion on freeipa-devel mailing list [1].

[1] https://lists.fedoraproject.org/archives/list/freeipa-devel@lists.fedorahosted.org/message/4VAWJ4SFKKBFFICDLQCTXJWRRQHIYJLL/

Reviewed-By: Michal Reznik <mreznik@redhat.com>

ipatests/setup.py

@@ -50,6 +50,7 @@ if __name__ == '__main__':
         ],
         scripts=['ipa-run-tests', 'ipa-test-config', 'ipa-test-task'],
         package_data={
+            'ipatests': ['prci_definitions/*'],
             'ipatests.test_install': ['*.update'],
             'ipatests.test_integration': ['scripts/*'],
             'ipatests.test_ipaclient': ['data/*/*/*'],