[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?
I don't think we shld recommend using sudo for npm because it can cause problems where you end up having to use sudo for everything node. sudo should not be needed to install dependencies for SUMO if you aren't using the -g flag (which also shouldn't be used).