fix: use v3 in baseURL when fetching GHE repos
Created by: KattMingMing
Resolves https://github.com/sourcegraph/sourcegraph/issues/440 by checking if we are fetching from GitHub Enterprise or GitHub and updating the baseURL accordingly.
Created by: KattMingMing
Resolves https://github.com/sourcegraph/sourcegraph/issues/440 by checking if we are fetching from GitHub Enterprise or GitHub and updating the baseURL accordingly.