Database class close method was not raising NotImplementedError

All other stubbed methods raise NotImplementedErrors. The close()
method did not raise the error. Now it does.

Author: rouilj

roundup/hyperdb.py

@@ -1103,7 +1103,7 @@ def close(self):
         This method must be called at the end of processing.
 
         """
-
+        raise NotImplementedError
 
 def iter_roles(roles):
     ''' handle the text processing of turning the roles list