Add session migration

migrations/20180104141055-create-session-table.js

@@ -0,0 +1,23 @@
+'use strict';
+
+module.exports = {
+  up: (queryInterface, Sequelize) => {
+    return queryInterface.createTable('sessions', {
+      createdAt: Sequelize.DATE,
+      updatedAt: Sequelize.DATE,
+      
+      sid: {
+        type: Sequelize.STRING(32),
+        primaryKey: true
+      },
+      expires: Sequelize.DATE,
+      data: Sequelize.TEXT
+    }, {
+      charset: 'utf8mb4'
+    })
+  },
+
+  down: (queryInterface, Sequelize) => {
+    return queryInterface.dropTable('sessions');
+  }
+};