Add --json option to node-group-template-show
Add --json option to node-group-template-show

Allows for exporting of node group template in a JSON representation

Change-Id: I98e991f62bdcc97c374722f364268700471fb9a3
Implements: blueprint python-savannaclient-cli

openstack/python-saharaclient,citrix-openstack-build/python-saharaclient,citrix-openstack-build/python-saharaclient,citrix-openstack-build/python-saharaclient