Add mybinder link to run notebooks in online environment

[gschivley]

I mentioned this to Jesse, but you might consider adding a Project.toml file and a mybinder link/badge to run the notebooks in a free online environment (https://mybinder.readthedocs.io/en/latest/howto/languages.html#julia). I've done it for python classes/workshops and a simple battery optimization model. Provides a nice way for people to run code without having to install anything.

[east-winds]

I started a branch (mybinder) and pushed a basic binder integration.
6b93c36