initial draft of 'Why not Pivotal Tracker'
Update 2013-06-07-why-pivotal-tractor.md

Is a change on this branch reflected on the pull request?
Update 2013-06-07-why-pivotal-tractor.md

some edits
Update 2013-06-07-why-pivotal-tractor.md

dont capital Agile
Update 2013-06-07-why-pivotal-tractor.md

embed image
Merge branch 'master' into why-pivotal