Run upload-npm role on executor

The upload-npm role seems to expect to upload files from the
executor, so in the javascript post playbook we should tell it to
run on localhost rather than the job node.

Change-Id: Iee176655108362545029f87134e9f150e0e35c17

playbooks/javascript/post.yaml

@@ -3,4 +3,7 @@
     - fetch-javascript-output
     - version-from-git
     - fetch-javascript-tarball
+
+- hosts: localhost
+  roles:
     - upload-npm