Started with `localstack start` then navigated to `http://localhost:4569/shell`

Localstack version is `0.10.5`

![Screenshot from 2019-11-26 08-15-03](https://user-images.githubusercontent.com/57932946/69588919-24798700-1025-11ea-94d2-9cfb6dd20004.png)

Console log below, its all the same so I am just posting one

```2019-11-26T00:13:18:ERROR:localstack.services.generic_proxy: Error forwarding request: the JSON object must be str, bytes or bytearray, not NoneType Traceback (most recent call last):
  File "/opt/code/localstack/localstack/services/generic_proxy.py", line 240, in forward
    path=path, data=data, headers=forward_headers)
  File "/opt/code/localstack/localstack/services/dynamodb/dynamodb_listener.py", line 44, in forward_request
    data = json.loads(to_str(data))
  File "/usr/lib/python3.7/json/__init__.py", line 341, in loads
    raise TypeError(f'the JSON object must be str, bytes or bytearray, '
TypeError: the JSON object must be str, bytes or bytearray, not NoneType```

fix_headers_for_updated_response(response)
            return response
        elif action == '%s.TagResource' % ACTION_PREFIX or action == '%s.UntagResource' % ACTION_PREFIX:
            response = Response()
            response.status_code = 200
            response._content = ''  
            fix_headers_for_updated_response(response)
            return response
        elif action == '%s.ListTagsOfResource' % ACTION_PREFIX:
            response = Response()
            response.status_code = 200
            response._content = json.dumps({'Tags': []})  
            fix_headers_for_updated_response(response)
            return response
        return True
    def return_response(self, method, path, data, headers, response):
        if path.startswith('/shell'):
            return
        data = json.loads(to_str(data))
        
        if data and 'TableName' in data and 'KeySchema' in data:
            TABLE_DEFINITIONS[data['TableName']] = data
        if response._content:
            
            content_replaced = re.sub(r'("TableArn"|"LatestStreamArn"|"StreamArn")\s*:\s*"arn:aws:dynamodb:' +
            'ddblocal:([^"]+)"', r'\1: "arn:aws:dynamodb:%s:\2"' % aws_stack.get_region(),
            to_str(response._content))
            if content_replaced != response._content:
                response._content = content_replaced
                fix_headers_for_updated_response(response)