Extract Keystone v3 service catalog
Extract Keystone v3 service catalog

Fix #407

larsbutler/gophercloud,trumant/gophercloud,timbyr/gophercloud,jamiehannaford/gophercloud,feiskyer/gophercloud,DSpeichert/gophercloud,rackspace/gophercloud,DSpeichert/gophercloud,feiskyer/gophercloud,timbyr/gophercloud,jarosser06/gophercloud,larsbutler/gophercloud,dudymas/gophercloud,clintonskitson/gophercloud,carolynvs/gophercloud,carolynvs/gophercloud,jarosser06/gophercloud,rackspace/gophercloud,jamiehannaford/gophercloud,pratikmallya/gophercloud,trumant/gophercloud,clintonskitson/gophercloud,sti-jans/gophercloud,dudymas/gophercloud,sti-jans/gophercloud,pratikmallya/gophercloud