title: simple-salesforce result from bulk insert/upsert
body: <p>I am trying to match the output results to the input rows and from my test, it looks like bulk operation will return the result the same order but is it guaranteed?</p>
  <pre><code>input = [{json1},{json2},{json3},...]
  
  sf = Salesforce(instance='&lt;some instance&gt;', session_id='&lt;some session id&gt;')
  
  output = sf.bulk.some_table.upsert(json_data, 'key column', batch_size=1000, use_serial=False)
  
  
  df1 = pd.json_normalize(input)
  df2 = pd.json_normalize(output)
  
  summary_df = pd.merge(input, output, left_index=True, right_index=True)
  
  print(summary_df)
  </code></pre>