new_contents: from StringIO import StringIO
  from django.test.client import Client
  from couchforms.models import XFormInstance
  
  def spoof_submission(submit_url, body, name="form.xml", hqsubmission=True, headers={}):
      client = Client()
      f = StringIO(body.encode('utf-8'))
      f.name = name
      response = client.post(submit_url, {
          'xml_submission_file': f,
      }, **headers)
      if hqsubmission:
          xform_id = response['X-CommCareHQ-FormID']
          xform = XFormInstance.get(xform_id)
          xform['doc_type'] = "HQSubmission"
          xform.save()
      return response
subject: add util file (cherry picked from commit 4cdc47b3f2e1b94a722c1190a524f42336669914)