Build the doc using Documentup
Update README with quicker/simpler setup infos
Remove manual gem installation instructions

please use bundler in 2013
Remove gem therubyracer-heroku, no longer required

If you were previously using therubyracer or therubyracer-heroku, these gems are no longer required and strongly discouraged as these gems use a very large amount of memory.

https://devcenter.heroku.com/articles/rails-asset-pipeline