Implement the 'key_name' parameter in templates by adding the new property
to tacker_nfv_defs.yaml.
Change-Id: I1838b283a60c387a7cb92e6c8ebebe7ca8ac5141
Closes-Bug: #1578785
Tacker TOSCA templates are currently buried under tacker/devstack.
These samples templates are applicable for the whole project and they
are not related specifically to the devstack installation. Also,
segregate the new TOSCA parser based templates from the legacy ones
for easier deprecation when the time comes.
Change-Id: I35547335baf6827e6b7b10702d05276343d8ce75
Closes-Bug: #1579251