Dockerize

Added a Dockerfile that let me reproduce your basic pipeline.

To build it, I use `docker build -t wrightaprilm/squamates .` from the base directory. If you wanted to set up a build on Docker Hub (that would be triggered on every commit), I can help with that. Could even let it do your full `make`...

Additionally, I added `*.Rout` to the `.gitignore` so I didn't slurp up any of my outputs. You can still add new ones if you need to. Since I know little about your project/research, feel free to tell me to kick this back to just being the Dockerfile.

Cheers!

On a side note, pretty sure it was the :egg: that came first. :wink: I'll have to read the rest of the work here.