Adding security groups models and client

- Adding security groups request and response json models
- Adding security groups api client
- Adding security groups models metatests
- Updating test_network and test_port metatest considering a kwargs previous update
- Adding the security groups composite
- Adding the security groups config file

Change-Id: Icb1a249ebb7c992c0595e4274defb8e3c46cd4e7
Merge "Adding security groups models and client"