Fix bug 17 (#4254)

* fix gru_dygraph

* fix mmoe doc

* add args

PaddleRec/multi-task/MMoE/args.py

+#   Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserve.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# 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.
+
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+import argparse
+import distutils.util
+
+
+def parse_args():
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument(
+        "--base_lr", type=float, default=0.01, help="learning_rate")
+    parser.add_argument("--batch_size", type=int, default=5, help="batch_size")
+    parser.add_argument("--dict_dim", type=int, default=64, help="dict dim")
+    parser.add_argument(
+        "--emb_dim", type=int, default=100, help="embedding_dim")
+    parser.add_argument(
+        '--use_gpu', type=bool, default=False, help='whether using gpu')
+    parser.add_argument('--ce', action='store_true', help="run ce")
+    args = parser.parse_args()
+    return args