2.1.0

• Mark Sentry internal frames when using attach_stacktrace as in_app false (#786)
• Increase default severity of E_RECOVERABLE_ERROR to Severity::ERROR, instead of warning (#792)
• Make it possible to register fatal error listeners separately from the error listeners
  and change the type of the reported exception to \Sentry\Exception\FatalErrorException (#788)
• Add a static factory method to create a breadcrumb from an array of data (#798)
• Add support for SENTRY_ENVRIONMENT and SENTRY_RELEASE environment variables (#810)
• Add the class_serializers option to make it possible to customize how objects are serialized in the event payload (#809)
• Fix the default value of the $exceptions property of the Event class (#806)
• Add a Monolog handler (#808)
• Allow capturing the body of an HTTP request (#807)
• Capture exceptions during serialization, to avoid hard failures (#818)