update dssm simlary gamma parameter (#61)

Author: zzszmyf

deepmatch/models/dssm.py

@@ -60,7 +60,7 @@ def DSSM(user_feature_columns, item_feature_columns, user_dnn_hidden_units=(64,
     item_dnn_out = DNN(item_dnn_hidden_units, dnn_activation, l2_reg_dnn, dnn_dropout,
                        dnn_use_bn, seed=seed)(item_dnn_input)
 
-    score = Similarity(type=metric)([user_dnn_out, item_dnn_out])
+    score = Similarity(type=metric, gamma = 10)([user_dnn_out, item_dnn_out])
 
     output = PredictionLayer("binary", False)(score)