Add empty .npmignore file for periodic-package-stackviz-element
We actually want to publish the build folder in our tarball, this
allows jobs to use the final compiled output.
# NOTE(pabelanger): Delete npm mirror, since it is currently broken.
rm -rf ~/.npmrc
export DISPLAY=:99
+ # Because we want to publish the build folder, create an empty
+ # .npmignore file.
+ touch .npmignore
npm install --verbose
npm run prod --verbose
rm -rf .tox
