route config for space usage_summary

Author: jochenehret

config/routes.rb

@@ -276,6 +276,7 @@
   patch '/spaces/:guid', to: 'spaces_v3#update'
   delete 'spaces/:guid', to: 'spaces_v3#destroy'
   delete 'spaces/:guid/routes', to: 'spaces_v3#delete_unmapped_routes'
+  get '/spaces/:guid/usage_summary', to: 'spaces_v3#show_usage_summary'
   get '/spaces/:guid/relationships/isolation_segment', to: 'spaces_v3#show_isolation_segment'
   patch '/spaces/:guid/relationships/isolation_segment', to: 'spaces_v3#update_isolation_segment'
   get '/spaces/:guid/users', to: 'spaces_v3#list_members'