Upgrade to PubSubHubbub 0.4 (removing verify_token)

db/migrate/20160920003904_remove_verify_token_from_accounts.rb

@@ -0,0 +1,5 @@
+class RemoveVerifyTokenFromAccounts < ActiveRecord::Migration[5.0]
+  def change
+    remove_column :accounts, :verify_token, :string, null: false, default: ''
+  end
+end