Don't depend on coffee-rails gem.

[ugisozols]

Instead add it to Gemfile if it's not there when using template.
#1975

[krbullock]

Here I was just about to take a look at this, but you've already made the pull request. :) Thanks, looks good to me.

[parndt]

Doesn't Refinery have js.coffee files? How does this not break all of the javascripts with coffee?

[krbullock]

It adds it to the generated Gemfile in the :assets group. So it should still be available when needed, but now I can bundle install --without assets in my production environment and avoid an unnecessary dependency there.

[erithmetic]

It seems wrong that I should just "know" that my project needs coffeescript in order to compile assets for refinery. There should instead be a refinery-assets or refinery-js gem that depends on coffee, etc. that can go in the Gemfile's assets group.

[ugisozols]

coffee-rails dependency was brought back in 017ca9d and will be apart of 3.0.0.