v0.4.1

New features

• Add support for SparkPost
  docs
• Test with Django 1.10 beta

Other changes

• Requests-based backends (all but SparkPost) now raise
  AnymailRequestsAPIError for any requests.RequestException,
  for consistency and proper fail_silently behavior.
  (The exception will also be a subclass of the original RequestException,
  so no changes are required to existing code looking for specific
  requests failures.)