Log Message:
Update py-flask-admin to 1.4.0.

1.4.0
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* Updated and reworked documentation
* FileAdmin went through minor refactoring and now supports remote
  file systems. Comes with the new, optional, AWS S3 file management
  interface
* Configurable CSV export for model views
* Added overridable URL generation logic. Allows using custom URLs with
  parameters for administrative views
* Added column_display_actions to ModelView control visibility of the
  action column without overriding the template
* Added support for the latest MongoEngine
* New SecureForm base class for easier CSRF validation
* Lots of translation-related fixes and updated translations
* Bug fixes