GA run stability improvements.
- Add volume and snapshot removal to CloudCleaner test.
- Add CloudCleaner as last test to run in GA run test list to ensure all artifacts are cleaned up after tests run to prevent resource leaks.
- Increase terminate timeout for AutoScalingDescribeInstances test from 2 minutes to 3 minutes.
Removed AutoScalingCooldown test from CI-suite because it is unstable.
Merge pull request #201 from tbeckham/testing

GA run stability improvements.