refactor: migrate to PostgreSQL + Sequelize

server/models/folder.js

@@ -0,0 +1,24 @@
+'use strict'
+
+/**
+ * Folder schema
+ */
+module.exports = (sequelize, DataTypes) => {
+  let folderSchema = sequelize.define('folder', {
+    name: {
+      type: DataTypes.STRING,
+      allowNull: false
+    }
+  }, {
+    timestamps: true,
+    version: true,
+    indexes: [
+      {
+        unique: true,
+        fields: ['name']
+      }
+    ]
+  })
+
+  return folderSchema
+}