zone handling in Azure is potentially incorrect

The current azure implementation does not seem to be recognizing placement zones at all: https://github.com/CloudVE/cloudbridge/blob/master/cloudbridge/cloud/providers/azure/resources.py#L867
Instead, in azure, the region and zone are the same.
However, azure has support for zones in certain regions.
https://docs.microsoft.com/en-us/azure/availability-zones/az-overview