Implement git-{upload,receive}-pack handler
An implementation that's copied from gitlab-workhorse plus some tests. I moved handler functions to router
package so I can use the handler returned from NewRouter
directly in tests, otherwise handlers won't access params set by gorilla mux, and we won't be able to catch 404 errors due differences between router and the tests. cc/ @eReGeBe
Edited by GitLab Release Tools Bot