Fix permission denied on opening file /var/lib/clickhouse/status in integration tests.

tests/integration/helpers/cluster.py

@@ -1165,6 +1165,7 @@ class ClickHouseInstance:
 
         db_dir = p.abspath(p.join(self.path, 'database'))
         print "Setup database dir {}".format(db_dir)
+        os.mkdir(db_dir)
         if self.clickhouse_path_dir is not None:
             print "Database files taken from {}".format(self.clickhouse_path_dir)
             shutil.copytree(self.clickhouse_path_dir, db_dir)