Switch to fork of puppet-logstash

There was an issue in puppet-logstash such that if you updated the
content of the ssl keys used in the input::lumberjack it would not
restart the logstash service to use them. I was made the required
changes in our fork and have switched pp-puppet to use them.
Wrap up nginx so it will restart when DNS changes
Merge branch 'master' of github.com:alphagov/pp-puppet into env-ssl-prep
Merge pull request #40 from alphagov/env-ssl-prep

Env ssl prep