DataDog/dd-agent — pull request #557 by alq666 (2013-06-27 15:32:47+00:00)
Title: Fix postgresql.rollbacks metric and don't crash when tags are None.

postgresql.rollbacks metric was collecting the wrong data due to a typo.
chef-datadog 1.0.1 can create a tags entry with a None value, causing the the agent to crash. This is now fixed.