Fix coverage report generation with tox

Previously no coverage report was produced as the package name was
confusing the coverage module. We were also using the wrong command.

This also adds a coveragerc so that the results are sane.

Change-Id: I204f52eeae71ac11274431f9cdf518d19e42f94b

.coveragerc

@@ -0,0 +1,7 @@
+[run]
+branch = True
+source = os_collect_config
+omit = os_collect_config/tests/*,os_collect_config/openstack/*
+
+[report]
+ignore-errors = True

tox.ini

@@ -22,7 +22,7 @@ commands = flake8
 [testenv:cover]
 setenv = VIRTUAL_ENV={envdir}
 commands =
-  python setup.py testr --coverage
+  python setup.py test --coverage --coverage-package-name=os_collect_config
 
 [testenv:venv]
 commands = {posargs}