…dean)This PR was merged into the 2.8 branch.Discussion----------Use callable classes for custom Monolog processorsThe built-in Monolog processors all use callable classes with an `__invoke()` method, whereas the Symfony documentation uses a `processRecord()` method. Using `__invoke()` provides consistency with the standard processors and also removes the need to specify the method name in the service configuration.Commits-------6f1a0f3 Use callable classes for custom Monolog processors