Updates Vagrantfile
Updates Vagrantfile

* precise -> trusty
* Start in GUI mode now that X11 support is on the way

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ViDA-NYU/reprozip,ViDA-NYU/reprozip,JosuaKrause/reprozip,ViDA-NYU/reprozip,ViDA-NYU/reprozip,JosuaKrause/reprozip,JosuaKrause/reprozip,JosuaKrause/reprozip,ViDA-NYU/reprozip