Added migrations

ma-api/lib/models/marketalert.js

@@ -0,0 +1,10 @@
+'use strict';
+module.exports = (sequelize, DataTypes) => {
+  const MarketAlert = sequelize.define('MarketAlert', {
+    olx_url: DataTypes.STRING
+  }, {});
+  MarketAlert.associate = function(models) {
+    // associations can be defined here
+  };
+  return MarketAlert;
+};