(#68) Move open-vm-tools binary package to downloads.puppetlabs.com

This updates the default location for the OpenVM tools binary package to
downloads.puppetlabs.com, reflecting the move away from the (now removed)
GitHub downloads feature.

Signed-off-by: Daniel Pittman <daniel@rimspace.net>
Merge pull request #69 from daniel-pittman/feature/master/68-move-open-vm-tools-to-our-downloads-site

(#68) Move open-vm-tools binary package to downloads.puppetlabs.com