Fix needs HTTPS

[SaranjeetKaur]

When docker compose up is run it lists some error messages of which one is the "needs HTTPS" error as below:

workbench-1  | ◌ Links must use HTTPS <https://https.cio.gov/everything/>                                                
workbench-1  | episodes/l2-01-sharing_your_code.md:130 [needs HTTPS]: [The OpenScience Project](http://openscience.org/about-openscience/)                                                                                                          
workbench-1  | episodes/l2-01-sharing_your_code.md:197 [needs HTTPS]: [Open Source Initiative](http://opensource.org/)
workbench-1  | learners/setup.md:86 [needs HTTPS]: [this list](http://sourceforge.net/projects/git-osx-installer/files/)