Set up a simple peer-to-peer tunnel

I wanted a recipe that installs OpenVPN in point-to-point mode but there wasn't one.  It creates a key and stores it as an encrypted data bag, either on a Chef server or locally, on disk, in a data bag.  

This way, you can copy the encrypted data bag between peers, or the remote peer will automatically use the right key.

There's also a sample role that demonstrates how to set up one side of the tunnel.