option to set workers for ansible configured builders

templates/buildbot/master.cfg.j2

@@ -107,7 +107,7 @@ factory.addStep(steps.ShellCommand(
 c['builders'].append(
   util.BuilderConfig(
     name="{{builder_name}}",
-    workernames=["local-worker"],
+    workernames={{builder.worker_names|to_json}},
     factory=factory
   )
 )