lib/eventhub/configuration.rb
def deep_merge!(target, data)
      return if data.nil?
      merger = proc do |_, v1, v2|
        v1.is_a?(Hash) && v2.is_a?(Hash) ? v1.merge(v2, &merger) : v2
      end
      target.merge! data, &merger
    end
def deep_merge!(target, data)
      return if data.nil?
      merger = proc do |_, v1, v2|
        v1.is_a?(Hash) && v2.is_a?(Hash) ? v1.merge(v2, &merger) : v2
      end
      target.merge! data, &merger
    end
Deep merging of hashes
 deep_merge by Stefan Rusterholz, see http://www.ruby-forum.com/topic/142809