Added nginx vhost for health checks
Added some packages that will assist with development
Added comments
Added missing inheritance
Ensure that Phabricator base directory exists
Purge unmanaged files from `/etc/nginx/conf.d/`
Subscribe `phd` service to phabricator and libphutil repositories
Revert "Simplified nginx config"

This reverts commit 00bd618e84a8ff52d945e56df6f22f4b21bf37f1.

This commit can be re-applied once https://github.com/jfryman/puppet-nginx/pull/200 is merged.
Enabled gzip for nginx.

This can be reverted when https://github.com/jfryman/puppet-nginx/issues/256 is fixed.
Upgraded `puppetlabs/mysql` dependency to v2.2.0
Specify hostname using environment variables
Changed VirtualBox name
Upgraded `puppetlabs/apt` module to v1.4.1
Change `HOSTNAME` environment variable to `DOMAIN`
Use the host resolver as a DNS proxy
Use the `vagrant-hostmanager` plugin.

`vagrant-hostmanager` is a Vagrant plugin that manages the `/etc/hosts` file on guests within a multi-machine environment.
Minor reorganization of `Vagrantfile`
Added a `phabricator-db` host
Use the `vagrant-cachier` plugin.

`vagrant-cachier` shares a common package cache among similiar VM instances.
Use the `vagrant-auto_network` plugin.

This plugin takes care of assigning IP addresses (within a default pool range of 10.20.1.2/24) to vagrant machines.