DP-69 REST server should keep running at end of blue-green deployment

Fixed issue where the REST server was terminating at the end of blue-green deployment. Instead it should keep running and report TERMINATING status.
Also removed unused classes originally added for earlier design of blue-green deployment.

Signed-off-by: Steffan Westcott <steffan.westcott@clicktravel.com>
Merge pull request #14 from clicktravel-steffan/master

DP-69 REST server should keep running at end of blue-green deployment