Check for correct URL for public vs private repos

[aidanheerdegen]

Private GitHub repos should use [email protected]:org/repo.git URLs, whereas https URLs are preferred for public repos.

This was highlighted in this issue

#155

which broke automated CI style builds that rely on SSH keys to access a private repo.

It should be possible to add a CI QA test to check the code URLs and make sure https is used for public GitHub repos, and git URLs for private.

[penguian]

See in partcular issue #158 which asks to revert pull request #155