More verbose logging if a Job throws an exception

Presently, the logger just logs the primary error message with no stack trace of additional debugging information. Type casting the exception to a string gives a much efficient output  and enables better debugging.

Author: Dayson Pais

lib/Resque/Worker.php

@@ -241,7 +241,7 @@ public function perform(Resque_Job $job)
 			$job->perform();
 		}
 		catch(Exception $e) {
-			$this->logger->log(Psr\Log\LogLevel::CRITICAL, '{job} has failed {stack}', array('job' => $job, 'stack' => $e->getMessage()));
+g			$this->logger->log(Psr\Log\LogLevel::CRITICAL, '{job} has failed {stack}', array('job' => $job, 'stack' => (string)$e);
 			$job->fail($e);
 			return;
 		}