Feature/mybinder ready

[kopp]

I created the necessary Project.toml so that this repo can be run on mybinder.org.

I tested this with my fork and got

https://mybinder.org/v2/gh/kopp/JuliaBoxTutorials/82e2f65176b96e9c2fa179c4b2d27cb0036e8492

which seemed to work fine.

I also left a mybinder link which should work with this repo once the PR is accepted.

[NHDaly]

Let's wait for a decision on the conversation in #56: as to how exactly we want the README to look. Thanks for this contribution! :)

Additionally, i'm torn about whether or not it's beneficial to have top-level .toml files in this repo:

• On the one hand, it's of course nice to have the repo come preloaded with all the packages users will need, and it's nice to freeze the versions of all the packages used so that these tutorials won't get stale.
• On the other hand, since this is meant to be an introduction to completely new julia users, if they run this locally on their machine, they may be surprised if when they switch to a different directory, any packages that they installed are no longer present (since they'll be editing this Project.toml, rather than the top-level shared julia environment). I do think that might be an awkward way to learn.

I considered adding this myself, too, before I saw your PR. I'm still not sure which is the better choice.

[kopp]

Would it work to have multiple Package.toml files? One in the toplevel containing everything and multiple ones containing only "what is necessary" in the subfolders?

I'm pretty new to Julia myself and all I wanted was to play with it in jupyter -- which did not work without the Package.toml...

[logankilpatrick]

@kopp if you want to update this PR, happy to get it merged in. We need to update the binder link and update the ReadMe links and such. I also second the notion to not include a project.toml file here.