Adds almost all coverage to the optimized driver

Implements coverage for all but one method of the Optimized NVP Driver.
Planning to do some cleanup on the security groups and rules logic in a
subsequent patch.
Merge pull request #149 from Cerberus98/op_driver_coverage

Adds almost all coverage to the optimized driver
Merge pull request #148 from kilogram/master

Update checks against default group.