Remove .vim directory if it is not manged by pivotal_workstation
Remove .vim directory if it is not manged by pivotal_workstation

If you use vim before running pivotal_workstation, git will refuse to
take over the .vim directory.  Fixes Issue 246.

webcoyote/pivotal_workstation,webcoyote/pivotal_workstation,1000Bulbs/pivotal_workstation,wendorf/sprout-osx-apps,Yesware/sprout,wendorf/sprout-osx-apps,wendorf/sprout-osx-apps,Yesware/sprout,1000Bulbs/sprout,Yesware/sprout,pivotal-sprout/sprout-osx-apps,1000Bulbs/pivotal_workstation,pivotal-sprout/sprout-osx-apps,webcoyote/pivotal_workstation,pivotal-sprout/sprout-osx-apps,1000Bulbs/sprout