updates to Spring2014 install script ubuntu-install.sh

- includes pull request https://github.com/saasbook/rag/pull/40
- Gemfile.lock, .travis.yml, ubuntu-install.sh
- in sync with set up for Spring2014 branches on rag and hw
- merge with https://github.com/saasbook/rottenpotatoes/tree/hw3_solution  which is used for deployment?