Wrote out test plan for ip addresses
Added test case for successful ip creation with network_id and device_id, reformatted comments for pep8
Refactored create method invocations into base class methods
Updated stub ip_address methods to be compatible with rest of API
Added failure test for creating ip address with invalid network_id and device_id
Added missing import
Added test for creating ip address with port_id; also, some test cleanup
Added test for creating ip address with invalid port_id
Fixed typo in test method names
Added test for create_ip_address with none of network_id, device_id, nor port_id
Added test for create_ip_address with network_id without device_id
Added test for create_ip_address without network_id and with device_id; also, docstring cleanup
Added test for create_ip_address with version 4 specified
Added test for create_ip_address with version 6 specified
Added failure test for create_ip_address with version 10 specified
Added test for create_ip_address with specific ip_address when ip_address doesn't exist
Added test for create_ip_address with specific ip_address when ip_address does exist already
pep8 cleanup
Updated TODO
Added test for update_ip_address when specific ip_address doesn't exist