Making delete_on_termination configurable

In the compute.create_test_server method the delete_on_termination
parameter for the block device mapping is hard coded to be True, this
change allows to pass it as keyword argument, if it is not passed we
keep True as default value.

Change-Id: I38fea4c9e0aca0d0c2fb97fd7d323c4e808ae050
1 file changed