UX (?) bug: ugly error if you don't have access to see collaborators on a repo

[antislice]

Stems from what I saw on #18. Github returns a 403 error if you don't have push access: GET https://api.github.com/repos/calagator/calagator/collaborators?per_page=100: 403 - Must have push access to view repository collaborators. (for example)

Fix would probably be to catch that error & not save collaborator info when creating Contributors. Or checking on the permissions of the person running osbot up front & not even making that call to github to get the collaborators. Then someone would just see the list of usernames with scores.

Or, the decision could be made to only have any of the app function if you at least have push access, in which case a nice apologetic error message before trying to load anything would work.