Make the GitHub url into a config value

[asheliahut]

Changing the base url for GitHub will allow support for GitHub Enterprise.

[0xtavian]

I implemented baseURL here https://github.com/0xtavian/shhgit/blob/master/core/session.go#L65 but when running on debug we are able to view the private GHE repos urls but unable to clone.

I believe the solution is to also support basic authentication.

"Turns out that {Github Enterprise} uses the token as a password for your user, so it requires a basic authentication rather than a token in the header." https://stackoverflow.com/questions/51751828/clone-a-repository-from-github-enterprise-with-go-git

[eth0izzle]

Closed. See #38