Code review comment for lp:~viswesn/juju-ci-tools/ensure_provider_cleanup

Chris, I updated the code by taken up almost all the review comments provided and more over in the current code review I removed the test case "TestGetSecurityGroups" because I need to discuss with you on how to handle "get_all_security_groups" using Mock.

Let us discuss on this on coming Monday call or please let me know by mail how to address "get_all_security_groups" mock in returning the value. It also requires invoking sg.instance() based on the object that it returns. Thanks