3579 playbooks redirect

* Handles redirects for ryansplaybooks.com in VCL
* Updates README with varnishd startup documentation
* Updates Vagrantfile to use more recent Ubuntu image
That syntax is taken straight from [the example in the Varnish wiki](https://www.varnish-cache.org/trac/wiki/VCLExampleRedirectInVCL). I agree that `==` should be sufficient.

In the interest of time, I'm going to push this out as-is, so I don't need to spin up Vagrant locally to test the changes. But worth keeping in mind for future config that either variant might work.