new_contents: from StringIO import StringIO
  from django.core.management import call_command
  import pytest
  
  
  def test_for_missing_migrations():
      output = StringIO()
      try:
          call_command(
              'makemigrations', interactive=False, dry_run=True, exit_code=True,
              stdout=output)
      except SystemExit as e:
          # The exit code will be 1 when there are no missing migrations
          assert unicode(e) == '1'
      else:
          pytest.fail("There are missing migrations:\n %s" % output.getvalue())
  
subject: Add test to fail if there are migrations missing.