Fix exception that asyncio throws on GC

[andrey-git]

Description:

check_config script, which is now run during restart prints an exception due to asyncio/python bug: python/asyncio#456

Exception ignored in: <bound method _UnixSelectorEventLoop.__del__ of <_UnixSelectorEventLoop running=False closed=True debug=False>>
Traceback (most recent call last):
  File "/srv/hass/lib/python3.4/site-packages/asyncio/base_events.py", line 361, in __del__
  File "/srv/hass/lib/python3.4/site-packages/asyncio/unix_events.py", line 57, in close
  File "/srv/hass/lib/python3.4/site-packages/asyncio/unix_events.py", line 138, in remove_signal_handler
TypeError: signal handler must be signal.SIG_IGN, signal.SIG_DFL, or a callable object

This PR works around it by closing the asyncio loop before exit.

[mention-bot]

@andrey-git, thanks for your PR! By analyzing the history of the files in this pull request, we identified @rmkraus, @balloob and @jaharkes to be potential reviewers.

[pvizeli]

I can fix it without Workaround :) We Need mock the helper/Signal.py on check_config script and the Problem go away. This also not correct works on windows while we not use the default loop.