Add puppet as a development dependency

Author: robinbowes

pre-commit-puppet.gemspec

@@ -26,4 +26,5 @@ Gem::Specification.new do |s|
   s.add_development_dependency("minitest", "~> 4.0")
   s.add_development_dependency("minitest-reporters", "~> 0")
   s.add_development_dependency("rake", "~> 10.0")
+  s.add_development_dependency("puppet")
 end