Add backup recipe to gitlabhq

This commit adds a backup recipe for the repositories and the database.
It also adds a knife solo data bag to use with the backup recipe and
vagrant.
Include data_bag_path in spec helper

This commit configures chef to use the included data_bags directory as
part of the chefspec run.
Add spec for backup recipe

This commit adds spec tests for the backup recipe.
Merge pull request #32 from WideEyeLabs/add-backups

Add backups