Install task

Simply run `make install` to install all dependencies and build the project:

- Bundler & Gem dependencies (here: Sass)
- node modules
- bower components

It also launches a gulp build and mocha tests.

![screenshot 2014-11-06 17 10 50](https://cloud.githubusercontent.com/assets/85783/4940146/f3a3810a-65d7-11e4-8a48-8ed30959c7d6.png)

Should I `sudo` the installation of bundler, as it's needed on a default Mac OSX box?