Replace everything with Docker

[Baisang]

Now that Docker for Windows is a real thing, I'm going to look into replacing this repository with a Docker setup for devs.

The only reason I used vagrant initially was due to lack of Windows support for Docker.

[tmochida]

Docker for Windows is still in public beta, we should wait at least until it's out of beta. We don't want to be debugging Docker bugs when setting up candidates' machines,

The resource overhead from VMs are not going to heavily tax most laptops, and most students will end up using vagrant in CS classes. Not so sure about docker.

However, docker would be a good idea for our staging setup.

[Baisang]

Why don't we offer both? The reason I think docker is more interesting is because it's not taught or used in any classes so far. And I think it would be superior dev environment for other Linux and even osx users.

[Baisang]

Docker for Windows is not less resource heavy than a vm btw, because I think how it works is that it runs on a vm (lol). Just thought it would be good to expose committee members with technologies used outside of the classroom that do make setup simpler.