website: Use Pelican instead of Jekyll for convenience

Summary

Switch out Jekyll in favor of Pelican.

Pelican uses python, which allows us to create a python virtual environment in this project. This allows to run the project (optimistically) everywhere, without having to worry about everyone's local environments. This also works on the iastate linux computers if people are interested in using those.

Testing and Usage

I've tested this out on the iastate linux, and I can do the following:

1. Clone our project.
2. The first time the repo has been cloned, in the website branch, run "make setup"
3. Make a change to something in website/content/pages.
4. Run make deploy in the website folder.
5. See the results live at http://may1716.sd.ece.iastate.edu/
6. And no installation required!

Please review and merge if you approve: @dawehr @drahos