Assume that if VAGRANT_DEFAULT_PROVIDER is set we shouldn't install vbox tools
Changed docker apt repo URI from https to http because the http driver for apt is not installed by default
pr #1718: Fetch docker gpg over https
Merge pull request #1449 from spkane/honor-ENV-VAGRANT_DEFAULT_PROVIDER

Assume that if VAGRANT_DEFAULT_PROVIDER is set we shouldn't install vbox tools