title: result of response.json() causes " 'Response' object has no attribute 'read' " error
body: <p>I am trying to convert json from an external api to an xls file using requests and tablib. In order to do this, I send a request to the external api, which returns a valid json file. This is my code:</p>
  
  <pre><code>response = req.request("GET", url, params=querystring)
  response.json()
  data = tb.Dataset()
  data.json = response.read()
  </code></pre>
  
  <p>This is what I get:</p>
  
  <pre><code>Traceback (most recent call last):
    File "...\python\lib\tkinter\__init__.py", line 1705, in __call__
      return self.func(*args)
    File ".../python/Scripts/myscript", line 37, in submit
      data.json = response.read()
  AttributeError: 'Response' object has no attribute 'read'
  </code></pre>
  
  <p>If the code is, </p>
  
  <pre><code> response = req.request("GET", url, params=querystring)
   response.json()
   data = tb.Dataset()
   data.json = response.json()
  </code></pre>
  
  <p>I get: </p>
  
  <pre><code>Traceback (most recent call last):
    File "...\Bitnami\djangostack-3.0.5-1\python\lib\tkinter\__init__.py", line 1705, in __call__
      return self.func(*args)
    File "...\Bitnami/djangostack-3.0.5-1/python/Scripts/buzzsumo.py", line 37, in submit
      data.json = response.json()
    File "...\Bitnami\djangostack-3.0.5-1\python\lib\site-packages\tablib\formats\__init__.py", line 66, in __set__
      return self._format.import_set(obj, normalize_input(val))
    File "...\Bitnami\djangostack-3.0.5-1\python\lib\site-packages\tablib\formats\_json.py", line 38, in import_set
      dset.dict = json.load(in_stream)
    File "...\Bitnami\djangostack-3.0.5-1\python\lib\json\__init__.py", line 293, in load
      return loads(fp.read(),
  AttributeError: 'dict' object has no attribute 'read'
  </code></pre>
  
  <p>What am I doing wrong?</p>