db/primary_migrate/20170207192356_remove_unused_encrypted_otp_secret_columns.rb
class RemoveUnusedEncryptedOtpSecretColumns < ActiveRecord::Migration[4.2]
def change
remove_column :users, :encrypted_otp_secret_key_iv, :string
remove_column :users, :encrypted_otp_secret_key_salt, :string
end
end