Adding rails version to new migrations

db/migrate/20180118112809_add_datetaken_to_photos.rb

@@ -1,4 +1,4 @@
-class AddDatetakenToPhotos < ActiveRecord::Migration
+class AddDatetakenToPhotos < ActiveRecord::Migration[4.2]
   def change
     add_column :photos, :date_taken, :datetime
   end

db/migrate/20180205000612_remove_shop.rb

@@ -1,4 +1,4 @@
-class RemoveShop < ActiveRecord::Migration
+class RemoveShop < ActiveRecord::Migration[4.2]
   def up
     drop_table :order_items
     drop_table :orders

db/migrate/20180213005731_seed_usage.rb

@@ -1,4 +1,4 @@
-class SeedUsage < ActiveRecord::Migration
+class SeedUsage < ActiveRecord::Migration[4.2]
   def change
     # # seed can be all sown, meaning there is none left
     add_column(:seeds, :finished, :boolean, default: false)