Fix rubocop issues

db/schema.rb

@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # This file is auto-generated from the current state of the database. Instead
 # of editing this file, please use the migrations feature of Active Record to
 # incrementally modify your database, and then regenerate this schema definition.
@@ -11,8 +13,6 @@
 # It's strongly recommended that you check this file into your version control system.
 
 ActiveRecord::Schema.define(version: 0) do
-
   # These are extensions that must be enabled in order to support this database
-  enable_extension "plpgsql"
-
+  enable_extension 'plpgsql'
 end