This turns launch-node into an installable package. This is not meant
for distribution, we just encapsulate the installation in a virtualenv
on the bastion host. Small updates to documentation and simple
testing are added (also remove some spaces to make test_bridge.py
First of all, we're using RST syntax, so rename it to README.rst.
More importantly, remove menitons of puppetmaster - and puppet in
general, as they are distracting. When reading the file, my eyes
scanned and hit puppetmaster and I almost skipped the section with the
assumption it was out of date.