Update oslo.vmware to be >= 0.2

There are a number of bug fixes that deal with image and session
management.

Change-Id: I27e62ac6a6d4e0bbadf1be3dbc62d38cd68e9f58
Sets the minimum python-novaclient version to 2.17.0

python-novaclient 2.17.0 introduces external event support,
required for nova/neutron interaction.

Change-Id: I3c03bfccb38ec5029370daf25f60575bc3e00103
Merge "Update oslo.vmware to be >= 0.2"