Change worker exit to use exit instead of exit!.

`exit!` causes any `at_exit` hooks used by performed code to be ignored.

Author: danp

lib/resque/worker.rb

@@ -128,7 +128,7 @@ def work(interval = 5.0, &block)
           else
             procline "Processing #{job.queue} since #{Time.now.to_i}"
             perform(job, &block)
-            exit! unless @cant_fork
+            exit unless @cant_fork
           end
 
           done_working
@@ -302,7 +302,7 @@ def kill_child
     def paused?
       @paused
     end
-    
+
     # Stop processing jobs after the current one has completed (if we're
     # currently running one).
     def pause_processing