Adding test_security_group_rules_create_with_invalid_port_range

A negative test which verifies that a Security Group rule creation
with invalid port range fails.

In addition, fixing few pep8's identation errors.

Change-Id: I092201fb33392a28de88c68e5cf4b86e2e748a84
Merge "Adding test_security_group_rules_create_with_invalid_port_range"