Include caller info with the deprecation warning

Author: tarcieri

lib/resque/worker.rb

@@ -618,6 +618,7 @@ def very_verbose=(_); logger_severity_deprecation_warning; end
     def logger_severity_deprecation_warning
       return if $warned_logger_severity_deprecation
       puts "*** DEPRECATION WARNING: Resque::Worker#verbose and #very_verbose are deprecated. Please set Resque.logger.level instead"
+      puts "Called from: #{caller[0..5].join("\n\t")}"
       $warned_logger_severity_deprecation = true
       nil
     end