Pwned validator threshold

[philnash]

Adds a threshold to the PwnedValidator so that you can let less pwned passwords still be valid if you so choose.

class User < ApplicationRecord
  # The record is marked as valid if the password has been used once in the breached data
  validates :password, pwned: { threshold: 1 }
end

[kpumuk]

Looks super clean 👍