The ``sciencenet_spider.py`` example does not (seem to) work for python 3.6 about gain HOT 5 OPEN

python sciencenet_spider.py
[2018:04:14 22:32:58] Spider started!
[2018:04:14 22:32:58] Using selector: KqueueSelector
[2018:04:14 22:32:58] Base url: http://blog.sciencenet.cn/
[2018:04:14 22:32:58] Item "Post": 0
[2018:04:14 22:32:58] Requests count: 0
[2018:04:14 22:32:58] Error count: 0
[2018:04:14 22:32:58] Time usage: 0:00:00.001171
[2018:04:14 22:32:58] Spider finished!
Traceback (most recent call last):
  File "sciencenet_spider.py", line 19, in <module>
    MySpider.run()
  File "/Users/endafarrell/anaconda/anaconda3/envs/py35/lib/python3.5/site-packages/gain/spider.py", line 52, in run
    loop.run_until_complete(cls.init_parse(semaphore))
  File "/Users/endafarrell/anaconda/anaconda3/envs/py35/lib/python3.5/asyncio/base_events.py", line 467, in run_until_complete
    return future.result()
  File "/Users/endafarrell/anaconda/anaconda3/envs/py35/lib/python3.5/asyncio/futures.py", line 294, in result
    raise self._exception
  File "/Users/endafarrell/anaconda/anaconda3/envs/py35/lib/python3.5/asyncio/tasks.py", line 240, in _step
    result = coro.send(None)
  File "/Users/endafarrell/anaconda/anaconda3/envs/py35/lib/python3.5/site-packages/gain/spider.py", line 71, in init_parse
    with aiohttp.ClientSession() as session:
  File "/Users/endafarrell/anaconda/anaconda3/envs/py35/lib/python3.5/site-packages/aiohttp/client.py", line 746, in __enter__
    raise TypeError("Use async with instead")
TypeError: Use async with instead
sys:1: RuntimeWarning: coroutine 'Parser.task' was never awaited
[2018:04:14 22:32:58] Unclosed client session
client_session: <aiohttp.client.ClientSession object at 0x107259e48>

python
Python 3.5.5 |Anaconda, Inc.| (default, Mar 12 2018, 16:25:05)
[GCC 4.2.1 Compatible Clang 4.0.1 (tags/RELEASE_401/final)] on darwin