Update Vagrantfile to API version 2 - Fix #30

http://docs.vagrantup.com/v2

Fix #30

Signed-off-by: Rogerio Prado de Jesus <rogeriopradoj@gmail.com>
Merge pull request #31 from rogeriopradoj/fix-30

Update Vagrantfile to API version 2 - Fix #30
Merge pull request #1 from chad-thompson/master

merge from @chad-thompson