Back-fill test for create_vm retry in director

Signed-off-by: Rob Day-Reynolds <rdayreynolds@pivotallabs.com>
formatting

Signed-off-by: Rob Day-Reynolds <rdayreynolds@pivotallabs.com>
configurable max_vm_create_tries

Signed-off-by: Rob Day-Reynolds <rdayreynolds@pivotallabs.com>
Configurable max_vm_create_tries

instead of using a hard coded constant

Signed-off-by: Rob Day-Reynolds <rdayreynolds@pivotallabs.com>
Retry at most 15 times for OpenStack BAT

Signed-off-by: Rob Day-Reynolds <rdayreynolds@pivotallabs.com>