A team member (or self) has checked in a few bad commits into GitHub and broken the build. Here's how to move their commits into a new branch, and bring master back to green.
git pull origin development
git checkout -b prune
git push origin prune
git checkout development
git reset --hard 2c9ab34fe1bee4c0c124ab6da35e47c7ee020619
git push origin --force development
http://stackoverflow.com/questions/1057564/pretty-git-branch-graphs
http://bit-booster.com/graph.html
http://gitgraphjs.com/
http://gitgraphjs.com/examples/gitflowsupport.html
https://github.com/nicoespeon/gitgraph.js/tree/master/examples