simnet encoding bug fix (#3484)

* update

* update

* Update README.md

* Update run.sh

* Update utils.py

PaddleNLP/similarity_net/utils.py

+#encoding=utf-8
 #   Copyright (c) 2019 PaddlePaddle Authors. All Rights Reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -11,7 +12,6 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-# --coding=utf-8
 """
 SimNet utilities.
 """