Fix Asset Precompile Issue

[FifthSurprise]

Our gems (including Uglifier) and Rails/Heroku are not playing nicely.

Attempts to locally precompile assets to push up to Heroku fail: RAILS_ENV=production bundle exec rake assets:precompile complains about Backticks in the Javascript for some reason.

We also look into updating the gems we use and also get ourselves out of rails precompile hell if we can.

Meantime, I shut off uglifier which at least gets us working.

@michaelpelletier - One of us can start working on this when we get a chance.

[michaelpelletier]

Huh, that's weird. I didn't think we were using backticks in the JS because we're not on ES6, which is something I'd like to change eventually, but certainly hadn't started.