avoid breaking change for Heroku

Author: seuros

lib/closure_tree/configuration.rb

@@ -3,7 +3,7 @@ class Configuration # :nodoc:
     attr_accessor :database_less
 
     def initialize
-      @database_less = false
+      @database_less = ENV['DATABASE_URL'].to_s.include?('//user:[email protected]/')
     end
   end
 end