Add README about building Phoenix with Vagrant VMs

.gitignore

@@ -10,6 +10,7 @@ mydbstub.py*
 
 .idea
 .cache
+.vagrant
 
 /build
 /tmp

vagrant/README.rst

@@ -0,0 +1,38 @@
+Phoenix builds on various Linux distros with Vagrant
+====================================================
+
+Vagrant (https://www.vagrantup.com/) is a tool that enables creating and using
+automated, relatively lightweight virtual environments.  Vagrant and the
+Vagrant community provide several base images that are essentially simplistic
+bare-bones installs of various operating systems, that can be thought of as a
+bare canvas ready for provisioning with the needs of whatever applications
+they will be used for.
+
+For Phoenix, this means that we can automate the creation and provisioning of
+virtual Linux machines with all the packages installed that are needed for
+building Phoenix.  The subfodlers located in this folder contain the Vagrant
+configurations and a bootstrap script for all of the Linux distros that we
+currently support.
+
+
+Setup
+-----
+
+The following steps should be followed to set up a computer to be a Vagrant
+host:
+
+  1. Install VirtualBox: https://www.virtualbox.org/wiki/Downloads
+
+  2. Install vagrant: https://www.vagrantup.com/downloads.html
+
+  3. Install the vagrant-vbguest plugin to keep the VirtualBox Guest Additions
+     package installed and up to date. See: https://github.com/dotless-de/vagrant-vbguest
+     and run::
+
+         vagrant plugin install vagrant-vbguest
+
+
+Building
+--------
+
+TBW...