[OpenStack|Network] Add CRUD for SecurityGroup and SecurityGroupRules
White space cleanup
[OpenStack|Network] Display subnets as a child of Network
[OpenStack|Network] Add security_groups and security_group_rules hashes to the base Mock data
[OpenStack|Network] Add tests for security_groups and security_group_rules methods
Merge pull request #2593 from brandondunne/enhance_openstack_neutron_support

Enhance openstack neutron support