patch bundler to fetch from github over https

thanks @mrphs

Change-Id: Ic7523d12662b7211ffebf7134f3ce6b8c70b8fda
Reviewed-on: https://gerrit.instructure.com/30757
Reviewed-by: Brian Palmer <brianp@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>
QA-Review: Cody Cutrer <cody@instructure.com>