separate session for every request

bot.py

@@ -19,7 +19,6 @@ logging.basicConfig()
 
 bot = lib.MineBot(command_prefix='!')
 hn = heavynode.Client(HEAVYNODE_TOKEN)
-bot.add_cleanup(hn.shutdown)
 
 
 async def is_admin(ctx):

heavynode.py

@@ -13,7 +13,6 @@ class HttpError(Exception):
 class Client:
     def __init__(self, token):
         self.token = token
-        self.session = aiohttp.ClientSession()
         self.baseurl = 'https://control.heavynode.com/api'
         # global state is icky, but it sure is convenient
         loop = asyncio.get_event_loop()
@@ -35,7 +34,10 @@ class Client:
             path = '/' + path
         url = self.baseurl + path
 
-        r = await self.session.request(method, url, *args, **kwargs)
+        # use context managers so connection is properly closed after request
+        # we don't make many requests so this is reasonable
+        async with aiohttp.ClientSession() as session:
+            async with session.request(method, url, *args, **kwargs) as r:
                 if r.status >= 400:
                     raise HttpError(f'Request failed with status code {r.status}', r)
                 elif r.status == 204:
@@ -56,7 +58,3 @@ class Client:
         Assume there's only one."""
         r = await self.make_request('GET', '/client')
         self.server = r['data'][0]['attributes']
-
-    async def shutdown(self):
-        """Gracefully terminate HTTP session for shutdown."""
-        await self.session.close()