Adds delete method to EnginePoolSummary object.
Adds delete method to EnginePoolSummary object.

Since there isn't a delete_pool method directly on the Connection
object, this allows code to use the engine_pools return values for
deletion.

nbirnel/nexpose-client,jhart-r7/nexpose-client,tomhart-r7/nexpose-client,rapid7/nexpose-client,gschneider-r7/nexpose-client