Make pytest more verbose for easier debugging (canonical#5778)

When the pytest fails, its easier to debug if pytest is run in verbose mode.
Enable it.

Signed-off-by: Ani Sinha <anisinha@redhat.com>

tox.ini

@@ -132,7 +132,7 @@ commands =
     {envpython} -m json.tool --indent 2 {[files]network_v2} {[files]network_v2}
 
 [testenv:py3]
-commands = {envpython} -m pytest -m "not hypothesis_slow" --cov=cloudinit --cov-branch {posargs:tests/unittests}
+commands = {envpython} -m pytest -vv -m "not hypothesis_slow" --cov=cloudinit --cov-branch {posargs:tests/unittests}
 
 [testenv:py3-fast]
 deps =