add chat models

ChatService/app/models/chat.js

+var mongoose = require("mongoose");
+
+var chatSchema = new mongoose.Schema({
+    idUser : Number,
+    idDriver : Number,
+    history : [
+        {
+            from : Number,
+            to : Number,
+            message : String
+        }
+    ]
+});
+
+module.exports = mongoose.model("Chat", chatSchema);
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