Set up auto-wok githook

[mythmon]

When a new commit is pushed to master (or maybe another branch?) the server that hosts the site should pull new changes and regenerate the site.

[edunham]

Added build.sh a while back which will be all it takes to make Jenkins go when I finally get around to fixing #39. Setting up Jenkins on Twist is more or less worthless. Closing as duplicate of #39, even though this is totally the original :)