- This class is used to rotate a previously determined value to a new
one before making the comparions.
We use this at Shopify to rotate Basic Auth crendials but I can
imagine other use cases.
The implementation uses the same `Messages::Rotator` module than
the MessageEncryptor/MessageVerifier class so it works exactly the
same way.
You can use it as follow:
```ruby
rotator = ActiveSupport::SecureCompareRotator.new('new_production_value')
rotator.rotate('previous_production_value')
rotator.secure_compare!('previous_production_value')
```
