title: verify_jwt_in_request() returns None when called in custom Flask Decorator
body: <p>I am trying to create a custom decorator that makes use of <code>verify_jwt_in_request()</code> from the <code>flask-jwt-extended</code> library. My code is laid out as below:</p>
  
  <pre><code>@app.route("/test-auth", methods=["POST"])
  @custom_auth_required
  def test_auth():
      print(verify_jwt_in_request())
      print(get_jwt_identity())
      return Response(json.dumps({"test": "test"}), status=HTTP_200_OK, 
                      mimetype='application/json')
  
  
  def custom_auth_required(f):
  @wraps(f)
  def decorated(*args, **kwargs):
      params = request.json
      headers = request.headers
      print(verify_jwt_in_request())
      print(get_jwt_identity())
      try:
          if verify_jwt_in_request():
              print("validated")
          else:
              print("invalid")
          return f(*args, **kwargs)
      except KeyError:
          raise AuthError({"code": "something","description": "something else"}, 401)
  return decorated
  </code></pre>
  
  <p>For some reason my prints in both the API and the decorator return <code>None</code> for both <code>verify_jwt_in_request</code> and <code>get_jwt_identity</code>.</p>
  
  <p>Is there something am missing in my code?</p>