Added better signal name lookup

rq/worker.py

@@ -60,12 +60,16 @@ _signames = dict((getattr(signal, signame), signame)
 
 
 def signal_name(signum):
-    # Hackety-hack-hack: is there really no better way to reverse lookup the
-    # signal name?  If you read this and know a way: please provide a patch :)
     try:
-        return _signames[signum]
+        if sys.version_info[:2] >= (3, 5):
+            return signal.Signals(signum).name
+        else:
+            return _signames[signum]
+
     except KeyError:
         return 'SIG_UNKNOWN'
+    except ValueError:
+        return 'SIG_UNKNOWN'
 
 
 WorkerStatus = enum(