[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?
Still gives me trouble but I ditched it. I suppose there's something weird on my machine.