Fix parsing of puppet-lint --version

Summary: This seems to be off, at least for puppet-lint versions greater than 1.0.

Test Plan: arc unit

Reviewers: epriestley, Blessed Reviewers

Reviewed By: epriestley, Blessed Reviewers

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D11312