[WIP] - 422 elb rotate (#493)

* Initial work on certificate rotation.

* Adding ability to get additional certificate info.

* - Adding endpoint rotation.
- Removes the g requirement from all services to enable easier testing.

lemur/tests/test_validators.py

@@ -8,7 +8,6 @@ def test_private_key(session):
     from lemur.common.validators import private_key
 
     private_key(PRIVATE_KEY_STR)
-    private_key(PRIVATE_KEY_STR.decode('utf-8'))
 
     with pytest.raises(ValidationError):
         private_key('invalid_private_key')