Drop unused tables (#5630)

db/migrate/20180227161818_drop_unused_tables.rb

@@ -0,0 +1,10 @@
+class DropUnusedTables < ActiveRecord::Migration[5.1]
+  def up
+    drop_table :category_featured_users
+    drop_table :versions
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration
+  end
+end