Merge pull request #9 from jhesketh/master

Updates
Merge pull request #10 from jhesketh/master

Make user groups an array
Merge pull request #11 from jhesketh/master

Remove duplicate libmysqlclient-dev entry
Merge pull request #12 from jhesketh/master

Remove duplicated virutalenvwrapper package
Merge pull request #13 from jhesketh/master

Add in libffi-dev for dbci nodes
Locked down th users permissions as to what they can run via sudo.
Actually include the sudoers.d dir
Remove the admin group from the th_user

I added this in until the correct sudo commands were working