feat: add puppetboard role

- add nginx module to manage reverse proxy on host level
- add puppetboard venv
- add gunicorn instance
- add script to start the gunicorn instance
- add nginx vhost

site/profiles/templates/puppet/puppetboard/start_puppetboard.erb

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+<%= @virtualenv_dir %>/bin/gunicorn \
+    --workers <%= @gunicorn_workers %> \
+    --threads <%= @gunicorn_threads %> \
+    --config <%= @settings_file %> \
+    --bind <%= @gunicorn_bind %> \
+    puppetboard.app:app