Add encryption-type-delete to cinderclient

This modification adds support for deleting volume encryption types.
The encryption-type-delete command accepts a single argument, the
name or ID of the volume type whose associated encryption type should
be deleted. The encryption type may only be deleted if the associated
volume type is unused.

blueprint encrypt-cinder-volumes

Change-Id: Ie189e7ec91f5a8adc9d3496911de2811ad40f282
Merge "Add encryption-type-delete to cinderclient"