To use this generator you will need to have Yeoman, Node.js and NPM installed. You can do so through Homebrew on a Mac or manually on a PC/Linux.
brew install node
sudo npm install -g yeoman
Create a directory with the name you want the project to be called and cd in to it.
mkdir foobar
cd foobar
Install the generator in the new directory.
npm install git+ssh://git@github.com:UltraVisual/generator-somajs-mocha-karma.git
Generate a new project.
yo somajs-mocha