use develop branches for graviton/graviphoton

This will need to get reverted as soon as stable tags have been created in the repos.
For now I'm just letting this build a develop based vagrant box so that we can proceed
with development. In the end this will need to be done i a fashio that allows us to build
both develop/master and tag based vagrant boxen.
fix path to graviphoton

this way the scripts find the bower instance used by graviphoton.
continue grunt even if unit-tests fail
don't clear cache on new installs

This was failing and the cache should be empty at this stage anyhow.
remove old files from install and add new ones

Just some upstream changes that need to be done here...
add some errorish output

Surely we need to make this nicer (ie. write to stderr and abort install)
add some docs on prereq install

Since this is the first time I'm doing this on a more or less virgin machine, I'm finding
some deps that where missing from the setup.
bump centos version to 6.5
change box name for great win
use develop branch of puppet gravity module
use puppet forge api v3 with librarian-puppet
get rid of warning about module name