add cron service to obtain oauth token and store it to the DB

migrations/20190830134013-add-tokens-table.js

@@ -0,0 +1,27 @@
+'use strict';
+
+module.exports = {
+  up: (queryInterface, Sequelize) => {
+    return queryInterface.createTable('accessTokens', {
+      id: {
+        allowNull: false,
+        autoIncrement: true,
+        primaryKey: true,
+        type: Sequelize.INTEGER
+      },
+      token: Sequelize.TEXT,
+      validUntil: Sequelize.DATE,
+      createdAt: {
+        allowNull: false,
+        type: Sequelize.DATE
+      },
+      updatedAt: {
+        allowNull: false,
+        type: Sequelize.DATE
+      }
+    });
+  },
+  down: (queryInterface, Sequelize) => {
+    return queryInterface.dropTable('accessTokens');
+  }
+};