default to {} in both None or nonexistent case for bandwidth
Merge pull request #230 from TMaddox/fix_null_bandwidth

default to {} in both None or nonexistent case for bandwidth
unit test for when bandwidth is None
Merge pull request #231 from TMaddox/fix_null_bandwidth

unit test for when bandwidth is None
Using new exist object in callback
Merge pull request #233 from ramielrowe/callback_fix

Using new exist object in callback
Made Nova flavor field name configurable