Digital ocean deployment

Hi there,

I'm in the process of set up my own Sophie (or indeed Arthur) Tracker in preparation for our first child arriving soon, and added support for Digital Ocean to the Vagrantfile.

As mentioned in the README I've probably made some hideous mistakes here, but it should work for other people still. I am however having some problems with the stats page, which throws errors like this when trying to update, if you have any light you can shed on it that would be very appreciated!

  [Wed Jan 22 18:22:58 2014] [error] [client 82.3.239.104] PHP Fatal error:  Uncaught exception 'ErrorException' with message 'SessionHandler::write(): open(/var/www/sophietracker/app/storage/sessions/sess_8ibh11vt3pqdu615qc8l8im121, O_RDWR) failed: Permission denied (13)' in /var/www/sophietracker/bootstrap/compiled.php:2801\nStack trace:\n#0 [internal function]: Illuminate\\Exception\\Handler->handleError(2, 'SessionHandler:...', '/var/www/sophie...', 2801, Array)\n#1 /var/www/sophietracker/bootstrap/compiled.php(2801): SessionHandler->write('8ibh11vt3pqdu61...', '')\n#2 [internal function]: Symfony\\Component\\HttpFoundation\\Session\\Storage\\Proxy\\SessionHandlerProxy->write('8ibh11vt3pqdu61...', '')\n#3 [internal function]: session_write_close()\n#4 {main}\n  thrown in /var/www/sophietracker/bootstrap/compiled.php on line 2801