functional tests fail if cirros image not exist

The functional tests are looking for a cirros-*uec image and
if that isn't found they fail:

In the function novaclient/tests/functional/,
images variable is a generator object which doesn't have
'__getitem__' attribute and so the functional test is failing.

Change-Id: I32b05ff6f2c7501eff04fa9f180eecf3099389ab
Closes-Bug: 1615594
1 file changed