Use older version of puppetfile-resolver

Otherwise the Forge Push job fails as it's still using ruby 2.5.1

Author: Kevin Reeuwijk

Gemfile

@@ -70,3 +70,5 @@ extra_gemfiles.each do |gemfile|
   end
 end
 # vim: syntax=ruby
+
+gem 'puppetfile-resolver', '0.4.0'