labs: set OSBASH for export
labs: set OSBASH for export

Exporting VMs has not worked in a while. We need to set the OSBASH
variable for the export functions to do anything.

Change-Id: Ic30fed65d1f9993fcf37f89c3d8918086f252b4d

dguitarbite/OpenStack-Labs,openstack/training-labs,openstack/training-labs,dguitarbite/OpenStack-Labs,dguitarbite/OpenStack-Labs,openstack/training-labs