Updated with installation script for Ubuntu based systems. The script may be copied and pasted in full into a terminal session and to run as a single command.
1. Updated the "therubyracer for windows" link. The current one was 404.
2. Added an instruction about changing the dependencies. Without changing the dependencies bundle install will attempt to install an incompatible version of therubyracer .
GitHub has started to redirect raw.github.com to
raw.githubusercontent.com, breaking the installation scripts.
Paramter -L makes curl follow the redirect.