Add in tox -s cover support

Enable us to do code coverage tests

Change-Id: I586c0a64d2a351b38475afbae2c49d08cb5b5d55

.coveragerc

@@ -1,6 +1,9 @@
 [run]
 branch = True
 source = vmware_nsxlib
+omit = vmware_nsxlib/tests/*
 
 [report]
 ignore_errors = True
+[report]
+ignore_errors = True

tox.ini

@@ -69,9 +69,8 @@ deps = -r{toxinidir}/test-requirements.txt
 commands = bandit -r vmware_nsxlib -n 5 -ll
 
 [testenv:cover]
-basepython = python2.7
 commands =
-  python setup.py testr --coverage --testr-args='{posargs}'
+  python setup.py test --coverage --coverage-package-name=vmware_nsxlib --testr-args='{posargs}'
   coverage report
 
 [testenv:venv]