Ec2 Service Catalog tests

Work In progress PR
Instead of cloud_providers, I believe you will want to use provider_by_type to just get the ec2 providers
    http://cfme-tests.readthedocs.org/modules/utils/utils.testgen.html#utils.testgen.provider_by_type

...and then pick a random ec2 provider that is returned.  Not saying its the best approach but here is an example of that...  cfme/tests/infrastructure/test_vm_power_control.py#L27