Initial support for single instance MongoDB support

This code adds ability to create/delete instance
with mongodb service type. No other operations are supported.

Blueprint: single-instance-mongodb-ga

Change-Id: I3d2992dce02dec22d09cedee6bbfbf51286b9b3b
Backup support for single instance MongoDB

Partially implements: blueprint single-instance-mongodb-ga

Change-Id: I2582c66e18847a0ca16221f7630f7719454eef33