taskManager & recurrent events generation

server/migrations/20200129173454-user_email_index.js

@@ -8,12 +8,6 @@ module.exports = {
   },
 
   down: (queryInterface, Sequelize) => {
-    /*
-      Add reverting commands here.
-      Return a promise to correctly handle asynchronicity.
-
-      Example:
-      return queryInterface.dropTable('users');
-    */
+    return queryInterface.removeIndex('users', ['email'])
   }
-};
+}