Add config.json file generation

The Refstack UI JS expects a config.json file to tell it the base
URL of the API. Without this file, API calls cannot be made, so puppet
should generate this file.

Change-Id: I6ae9d18c22771561d18691faabe53ee575b9486b

manifests/app.pp

@@ -85,4 +85,11 @@ class refstack::app () {
       'HOME=/home/refstack'
     ]
   }
+
+  # Create config.json file
+  file { "${src_www_root}/refstack-ui/app/config.json":
+    ensure  => file,
+    content => '{"refstackApiUrl": "/api/v1"}',
+    require => Vcsrepo[$src_www_root],
+  }
 }