Refactor utils and organize routes/schema

schema/session.model.js

@@ -0,0 +1,19 @@
+const mongoose = require('mongoose');
+const Schema = mongoose.Schema;
+
+// Database schema for a session
+let Session = new Schema({
+    userId: {
+        type: String
+    },
+    sessionId: {
+        type: String
+    },
+    date: {
+        type: Date
+    }
+}, {
+    collection: 'sessions'
+});
+
+module.exports = mongoose.model('Session', Session);