Need to fix vagrant development environment setup since upgrades

[GUI]

Since the big Rails and Ember upgrades (#312), it turns out the admin part of the app won't load by default in a fresh Vagrant setup. We were able to workaround the issue by running the following commands inside vagrant ssh:

cd /vagrant-admin-ui
yarn
./node_modules/.bin/bower install
sudo /etc/init.d/api-umbrella restart

However, we need to fix this so the default setup works.

[GUI]

Should be resolved by NREL/api-umbrella-cookbook@5c6b64b and 16967c3