Clean challenge module.

letsencrypt/client/challenge.py

@@ -1,12 +1,13 @@
-from letsencrypt.client import logger
-
-
 class Challenge(object):
+
     def __init__(self, configurator):
         self.config = configurator
+
     def perform(self, quiet=True):
-        logger.error("Error - base class challenge.perform()")
+        raise NotImplementedError()
+
     def generate_response(self):
-        logger.error("Error - base class challenge.generate_response()")
-    def clean(self):
-        logger.error("Error - base class challenge.clean()")
+        raise NotImplementedError()
+
+    def cleanup(self):
+        raise NotImplementedError()