add guardian email field to the appearance release public signing form

db/migrate/20200612121539_add_guardian_email_to_appearance_releases.rb

@@ -0,0 +1,5 @@
+class AddGuardianEmailToAppearanceReleases < ActiveRecord::Migration[6.0]
+  def change
+    add_column :appearance_releases, :guardian_email, :string
+  end
+end