memorydb fixes for otks tests.

in test setup otks was not set. Also fixed import from dbm used by
memorydb OneTimeKeys to inherit from OneTimeKeys rather than Sessions.

Author: rouilj

roundup/test/memorydb.py

@@ -201,7 +201,7 @@ def clean(self):
 class Sessions(BasicDatabase, sessions_dbm.Sessions):
     name = 'sessions'
 
-class OneTimeKeys(BasicDatabase, sessions_dbm.Sessions):
+class OneTimeKeys(BasicDatabase, sessions_dbm.OneTimeKeys):
     name = 'otks'
 
 class Indexer(indexer_dbm.Indexer):

test/test_memorydb.py

@@ -62,6 +62,7 @@ def setUp(self):
         self.db = self.module.Database(config, 'admin')
         setupSchema(self.db, 1, self.module)
         self.sessions = self.db.sessions
+        self.otks = self.db.otks
 
     # doesn't work for memory as it uses a mock for session db.
     def testUpdateTimestamp(self):