Throw an error if we try to use git but it isn't installed (#362)
Make the code a little clearer
Merge pull request #503 from wibblymat/issue-362

Throw an error if we try to use git but it isn't installed (#362)
Close GH-507: Add --quiet and --silent command line options. Fixes #343
Close GH-237: Adding flexibility with endpoints. Fixes #232
Add types for all options.