naga v1.0

Naga is a terminal implementation of snake game. URL: http://github.com/anayjoshi/naga.
This is a first time addition of this project in homebrew. The project has existed for quite some time, the github repository was refurnished today.
>  Also, shouldn't the first case use /usr/local/Cellar/scons/2.3.1/bin/scons ?

The `opt` directory is a symlink to the latest installed scons, so they are the same.