[bug 1039523] Infrastructure for instant search

This does several things:
- Adds nunjucks and grunt to NPM dependencies
- Adds a `Gruntfile` to create grunt tasks to make development easier
- Adds a new manager command to precompile nunjucks templates
- Updates travis and deploy scripts to precompile nunjucks templates
- Updates the search view to return more consistent data in JSON format

r?
What did you need sudo for? I can install nunjucks just fine without it. I suspect that you have previously used sudo and so some things were owned by root, which means you can't do anything without sudo. Try and delete your node_modules directory and `npm install` again.