Change git protocol to https protocol in Gemfile for GitLab 5.0
Created by: bbodenmiller
Changes gems to use https protocol rather than the git protocol for GitLab 5.0 release. Git protocol does not work behind some firewalls and/or proxies. This change helps users upgrading from 4.2 to 7.1 have a smoother upgrade process. Fixes https://github.com/gitlabhq/gitlabhq/issues/3416 & https://github.com/gitlabhq/gitlabhq/issues/3478.