Update periodic-package-stackviz-element job

Use the new package build by gulp, this includes everything we now
need to properly pip install.

Change-Id: Ia9cc6533655c9476b2040ded0914b1fbedeb06aa
Signed-off-by: Paul Belanger <pabelanger@redhat.com>

jenkins/jobs/infra.yaml

@@ -461,11 +461,7 @@
           touch .npmignore
           npm install --verbose
           npm run prod --verbose
-          rm -rf .tox
-          rm -rf node_modules
-          npm pack --verbose
-          mkdir -p dist
-          mv *.tgz dist/stackviz-latest.tar.gz
+          mv dist/stackviz*.tar.gz dist/stackviz-latest.tar.gz
 
     publishers:
       - tarball: