Fix Python 3 incompatibilities

supervisor/process.py

@@ -456,7 +456,7 @@ class Subprocess(object):
 
         try:
             options.kill(self.pid, sig)
-        except Exception, e:
+        except Exception as e:
             io = StringIO.StringIO()
             traceback.print_exc(file=io)
             tb = io.getvalue()

supervisor/rpcinterface.py

@@ -512,7 +512,7 @@ class SupervisorNamespaceRPCInterface:
         if group is None:
             raise RPCError(Faults.BAD_NAME, name)
 
-        processes = group.processes.values()
+        processes = list(group.processes.values())
         processes.sort()
         processes = [(group, process) for process in processes]