old_contents: __version__ = '1.3rc1'
  default_app_config = 'wagtail.wagtailcore.apps.WagtailCoreAppConfig'
  
  
  def setup():
      import warnings
      from wagtail.utils.deprecation import removed_in_next_version_warning
  
      warnings.simplefilter("default", removed_in_next_version_warning)
  
  setup()
  
new_contents: __version__ = '1.4a0'
  default_app_config = 'wagtail.wagtailcore.apps.WagtailCoreAppConfig'
  
  
  def setup():
      import warnings
      from wagtail.utils.deprecation import removed_in_next_version_warning
  
      warnings.simplefilter("default", removed_in_next_version_warning)
  
  setup()
  
subject: Bump version on master to 1.4 pre-alpha