Add in more model changes around execution environments

- a new unique name field to EE
- a new configure-Tower-in-Tower setting DEFAULT_EXECUTION_ENVIRONMENT
- an Org-level execution_environment_admin_role
- a default_environment field on Project
- a new Container Registry credential type
- order EEs by reverse of the created timestamp
- a method to resolve which EE to use on jobs

awxkit/awxkit/api/pages/execution_environments.py

@@ -18,7 +18,7 @@ log = logging.getLogger(__name__)
 class ExecutionEnvironment(HasCreate, base.Base):
 
     dependencies = [Organization, Credential]
-    NATURAL_KEY = ('organization', 'image')
+    NATURAL_KEY = ('name',)
 
     # fields are image, organization, managed_by_tower, credential
     def create(self, image='quay.io/ansible/ansible-runner:devel', credential=None, **kwargs):