Import exception from pylint.exceptions instead of utils

Also tries to use the newer name (already over three years old) first.

Fixes #15

Author: michael-k

pylint_plugin_utils/__init__.py

@@ -1,8 +1,8 @@
 import sys
 try:
-    from pylint.utils import UnknownMessage
+    from pylint.exceptions import UnknownMessageError as UnknownMessage
 except ImportError:
-    from pylint.utils import UnknownMessageError as UnknownMessage
+    from pylint.exceptions import UnknownMessage
 
 
 def get_class(module_name, kls):