fix item categories API.

server/src/database/migrations/20190822214306_create_items_categories_table.js

@@ -2,7 +2,7 @@
 exports.up = function (knex) {
   return knex.schema.createTable('items_categories', (table) => {
     table.increments();
-    table.string('label');
+    table.string('name');
     table.integer('parent_category_id').unsigned();
     table.text('description');
     table.integer('user_id').unsigned();