Replaced apt with homebrew commands for Mac
Merge pull request #3 from mattjmorrison/patch-1

Replaced apt with homebrew commands for Mac
Bug Fix: Made ctrl-d issue exit command as expected
Merge branch 'master' of http://github.com/JarrodCTaylor/imt_dotfiles
Bug Fix: Removed redundant virtualenvwrapper line

This line:
`source /usr/local/bin/virtualenvwrapper.sh`

is unnessisary because of these two lines:
```
[[ -a /usr/local/share/python/virtualenvwrapper.sh ]] && source /usr/local/share/python/virtualenvwrapper.sh
[[ -a /usr/local/bin/virtualenvwrapper.sh ]] && source /usr/local/bin/virtualenvwrapper.sh
```

This was causing an error because in my specific instance my
`virtualenvwrapper.sh` file only existed under `/usr/local/share`