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```

existing_item = self._thread_local('existing_item')
                record['eventName'] = 'INSERT' if not existing_item else 'MODIFY'
                keys = dynamodb_extract_keys(item=data['Item'], table_name=data['TableName'])
                if isinstance(keys, Response):
                    return keys
                
                if response._content == '{}':
                    response._content = json.dumps({'Attributes': data['Item']})
                    fix_headers_for_updated_response(response)
                
                record['dynamodb']['Keys'] = keys
                record['dynamodb']['NewImage'] = data['Item']
                record['dynamodb']['SizeBytes'] = len(json.dumps(data['Item']))
                if existing_item:
                    record['dynamodb']['OldImage'] = existing_item
        elif action == '%s.GetItem' % ACTION_PREFIX:
            if response.status_code == 200:
                content = json.loads(to_str(response.content))
                
                
                if 'ConsumedCapacity' not in content and data.get('ReturnConsumedCapacity') in ('TOTAL', 'INDEXES'):
                    content['ConsumedCapacity'] = {
                        'CapacityUnits': 0.5,  
                        'TableName': data['TableName']
                    }
                    response._content = json.dumps(content)
                    fix_headers_for_updated_response(response)
        elif action == '%s.DeleteItem' % ACTION_PREFIX:
            if response.status_code == 200:
                old_item = self._thread_local('existing_item')