updated version, deps, and properly set mongo

I set this to only use the newest version of mongo 0.13.4. It now constrains it to this version instead of a >= or a ~ . I prefer this, because we now know what berks and chef will resolve the deps to. The ref in the berksfile was killing all cookbooks that included graylog2 as I believe the last reference to a cookbook gets precedence so 0.13.3 ( the broken mongodb build ) was still being referenced.