title: Django call_command() with filename wildcard
body: <p>How can you use filename wildcards in <code>call_command()</code>? I'm trying to create a management command that does the same as <code>python manage.py loaddata */fixtures/*.json</code></p>
  
  <p>Below code throws <code>CommandError: No fixture named '*' found.</code></p>
  
  <pre><code>from django.core.management import call_command
  from django.core.management.base import BaseCommand
  
  
  class Command(BaseCommand):
      help = 'Load all fixtures in app directories'
  
      def handle(self, *args, **kwargs):
          call_command('loaddata', '*/fixtures/*.json')
          self.stdout.write('Fixtures loaded\n')
  </code></pre>