Updates Vagrant file with new urls

Adds updated urls that use the new vagrant cloud images. I tried to use as simliar as possible to the exisitng boxes (puppet labs + puppet installed)
If user omits the flavor of OS to start, vagrant no longer attempts to start both instances. 

Fixes https://github.com/justindowning/puppet-influxdb/issues/6
Merge branch 'patch-1' of https://github.com/spuder/puppet-influxdb into spuder
simplify vm.box location for Vagrantfile
Update Vagrantfile with proper Vagrant Cloud URLs #6