Expanded CMTS emulator to accept at least one type of gate request. Future work will...

Expanded CMTS emulator to accept at least one type of gate request. Future work will allow for the ability to configure gates for validation. With an emulator that can accept gate requests, I have expanded the PCMMService tests to include setting and removal of a gate request to a single mock CMTS. Additionally, as I had encountered issues unmarshalling COPSDecisionMsg objects containing a gate request, another test has been included here (which may be better suited to be located in COPSDecisionMsgTest but the gate set mock object being used can only be used in this module) that creates and parses a COPSDecisionMsg object used for setting gates.

Change-Id: I98681f2514b88575a951f1e16a683ac046d32750
Signed-off-by: Steven Pisarski <s.pisarski@cablelabs.com>