Changed our acceptance test setup to pin on facter 2.1.0

Facter 2.2.0 changed the value returned from the 'lsbmajdistrelease'
fact that causes the postgresql module to break on Ubuntu 10.04. Pinning
facter to 2.1.0 avoids the problem until the module can be released.
Merge pull request #1080 from senior/maint/stable/pin-tests-to-facter-2-1-0

Changed our acceptance test setup to pin on facter 2.1.0