Added migrations and saving real estate type correctly

app/models/marketalert.js

@@ -0,0 +1,15 @@
+'use strict';
+module.exports = (sequelize, DataTypes) => {
+  const MarketAlert = sequelize.define('MarketAlert', {
+    olxUrl: DataTypes.STRING,
+    lastDate: DataTypes.STRING,
+    email: { 
+      type: DataTypes.STRING,
+      allowNul: false
+    }
+  }, {});
+  MarketAlert.associate = function(models) {
+    // associations can be defined here
+  };
+  return MarketAlert;
+};