improved loop handling

[samuelcolvin]

fixes #156
replaces #157

This package passed loops around a lot, this was mainly required for tests to pass with python < 3.5.2 where set_event_loop didn't work properly.

This in turn was causing problems with uvloop, either meaning the wrong loop was used or a "different loop" error occurred.

The fixes here can be demonstrated by the micro example

from aiohttp import web
import asyncio
import uvloop

async def handle(request):
    return web.Response(text=f'loop: {request.app.loop}')

asyncio.set_event_loop_policy(uvloop.EventLoopPolicy())
app = web.Application()
app.router.add_get('/', handle)

Run with

adev runserver demo.py

Should now return loop: <uvloop.Loop running=True closed=False debug=False> while before it was using the standard python loop.

@vladiibine would be great if you could try this and confirm it works for you.

[codecov]

Codecov Report

Merging #158 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #158      +/-   ##
==========================================
+ Coverage    94.9%   94.91%   +<.01%     
==========================================
  Files          13       13              
  Lines         766      767       +1     
  Branches       93       93              
==========================================
+ Hits          727      728       +1     
  Misses         25       25              
  Partials       14       14

Impacted Files	Coverage Δ
aiohttp_devtools/runserver/serve.py	94.29% <100%> (ø)	⬆️
aiohttp_devtools/version.py	100% <100%> (ø)	⬆️
aiohttp_devtools/runserver/config.py	88.37% <100%> (+0.09%)	⬆️
aiohttp_devtools/runserver/main.py	100% <100%> (ø)	⬆️

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[vladiibine]

Tested the changes, and at least the live reload works. Couldn't dwelve into the code more than this, so I don't get the full extent of the changes, but seems like it should be fine. I'll keep you updated if I find other issues :) Thanks a lot for yout time!

[samuelcolvin]

no problem, thanks.