Add a Vagrantfile

[IsaccBarker]

Add a Vagrantfile for some easier development. This should be relatively easy. I don't think Docker would be a good choice here.

The promise of Vagrant is including a Vagrantfile in your git repo, typing 'vagrant up' and magically provisioning an entire VM that's automatically mapped shared directories to your code base.

Docker is a platform for building container applications, while Vagrant is a tool that simplifies the creation and management of virtual machines.

Since epiworldpy isn't an application per se, and I do some development on NetBSD (where Docker doesn't like to play nice), I figure using Vagrant is fine.

[IsaccBarker]

I tried assigning this to a milestone but it keeps not saving; I'll try again tomorrow assuming this is an error with GitHub.

@IsaccBarker