Requests with the wrong token/reponame dont log errors

[himynameisdave]

Listen for status code on git requests in github request and handle errors better. Currently if the token or the reponame are invalid then the request still happens

[inakiarroyo]

@jasonbellamy Could you have a look at the ready PRs please? I opened 4 PRs resolving issues that I would like to have in if they are okay.

Thanks.