Use our new puppet puppet module and set version

1. We are now using the official Puppetlabs apt module instead of definining a
repository resource ourselves.
2. We're now using HTTP for the repository URL rather than HTTPS which didn't
work because the base VM on Skyscape doesn't have an apt_transport_https
package.
Ignore temporary and vagrant files
Give all accounts sudo

Bump to latest puppet-gds_accounts which allows multiple groups, and add all our
users to the sudo group as well as the gds group.

We're taking this approach rather than changing the sudoers file because we're
not happy with the module currently used for that in ci-puppet. We've raised a
story to look at how best to change the sudoers file instead:
https://www.pivotaltracker.com/story/show/55378608