Small fixes

Change-Id: Ie3268f382204b000fd77edf852fe60bdcb94b764
Remove unneeded requirements

Change-Id: Ic6068270b330a3185565a1e6483a294bdf2112cd
Catch novaclient.exceptions.NotFound error

Change-Id: I467597e545d9f79f5c1659c160329fb851098403