Add a section on mybinder

[tracykteal]

https://mybinder.org is live now and would be great to teach students how to use. To use it is

• put URL of github repo into https://mybinder.org
• copy code from the badge button to put into the README
• add that code to the README
• click on it to launch

We would also have to teach people how to use github to create repos and push files, but I think that would also be useful in this workshop, and was something that people requested in the R version.

[tracykteal]

In this lesson we could also add some information about mybinder, or examples of good mybinder uses. If people have ideas of what else to include in a my binder lesson, it would be great if they could add it to this issue. @choldgraf

[choldgraf]

Do you imagine having a specific lesson just on Binder? Or more like mention Binder throughout a course?

Also just a note that Binder is definitely not python specific, we worked with the R community to set up R support and now it's just a matter of developer hours to get in machinery that supports R build files!