Bug Fix: Fixed install url for homebrew

According to the installation instructions here: http://brew.sh/ the
correct url for installing homebrew is https://raw.github.com/mxcl/homebrew/go/install
Merge pull request #2 from mattjmorrison/homebrew_bug

Bug Fix: Fixed install url for homebrew
Merge pull request #1 from mattjmorrison/master

Feature: Streamlined installation process
Tech Debt: Removed rails from rvm install
Merge pull request #3 from mattjmorrison/patch-1

Tech Debt: Removed rails from rvm install
Feature: Added homebrew-cask and chrome, iterm and alfred

Homebrew Cask (https://github.com/phinze/homebrew-cask) provides a way
to install a majority of other OS X applications that are not normally
installable via homebrew.
Merge pull request #4 from mattjmorrison/patch-2

Feature: Added homebrew-cask and chrome, iterm and alfred
added tree
installer now does mongodb last as its really slow
installs firefox
Feature: Added virtualbox & vagrant to install
Tech Debt: Install vagrant & virtualbox after mongo
Tech Debt: install vagrant & virtualbox just before mongo
Tech Debt: Install vagrant & virtual box immediately before mongo
Merge pull request #6 from mattjmorrison/patch-3

Feature: Added virtualbox & vagrant to install
Removed mongodb (really slow install with brew)
reverted the installer (need to install git manually before running this script
add rvm install 2.0
added memcached
now installs setuptools as virtualenvwrapper >= 0.8