Log is spammed with resource warnings

[das7pad]

A resource warning is raised on every request to the api endpoints.

2017-06-27 23:28:50,498 - asyncio - ERROR - Unclosed client session
client_session: <aiohttp.client.ClientSession object at 0x7f007e8e8eb8>
2017-06-27 23:28:51,590 - asyncio - ERROR - Unclosed client session
client_session: <aiohttp.client.ClientSession object at 0x7f007e8f2898>
2017-06-27 23:28:51,898 - asyncio - ERROR - Unclosed client session
client_session: <aiohttp.client.ClientSession object at 0x7f007e8f2c88>
2017-06-27 23:28:52,102 - asyncio - ERROR - Unclosed client session
client_session: <aiohttp.client.ClientSession object at 0x7f007ab17ba8>
2017-06-27 23:28:52,359 - asyncio - ERROR - Unclosed client session
client_session: <aiohttp.client.ClientSession object at 0x7f007aaee668>

hangups version: 0.4.2
aiohttp version: 2.2.0

Pullrequest #326 addresses this issue for raised Exceptions during handling a response, but with the latest aiohttp update (mainly aio-libs/aiohttp#1985) the issue reached another level.

The cause for all the resource warnings: aiohttp==2.2.0 does not close the aiohttp.ClientSession created in aiohttp.request() anymore.