Block on instance delete until delete operation completes

Block on instance delete until delete operation completes

Fixes issue #160

During deletion of a stack, following would occur:
delete stack
delete instance
delete eip or security group

When the last operation occurred, the instance is still present in OpenStack
making a deletion of EIP or security groups not work properly.  Serialize
the operations in resources.

Change-Id: I6e1613f5a6f5db485dd8a5f381d7a96afb58188b
Signed-off-by: Steven Dake <sdake@redhat.com>