Added validation for vnfd-create
Added validation for vnfd-create

Modified vnfd.py

Change-Id: I9cf523beecc9ede93168bb370b48936cf2adca40
Closes-Bug: 1481446

trozet/python-tackerclient,openstack/python-tackerclient,stackforge/python-tackerclient,trozet/python-tackerclient,openstack/python-tackerclient,stackforge/python-tackerclient