Make `loop` fixture as alias for `event_loop`

[asvetlov]

In asyncio world parameter for event loop is always called loop, never event_loop.
I think we should use the same name for fixture (with keeping backward compatibility, sure).

Also disabling global loop by asyncio.set_event_loop(None) is useful feature.
I always run my tests in isolated environment.
Global loop may be an option (nondefault) for loop fixture.
event_loop should preserve existing global strategy but may accept option for disabling it (or we may keep it untouched encouraging people to use loop fixture).

[jettify]

any updates about this issue? Probably it is possible o add something like:

@pytest.fixture
def loop(event_loop):
   return event_loop

[dimaqq]

IMO loop is too generic for a magic name that pops up simple because one more testing library is installed.
Proposed work-around is simple enough.

Ultimately the preferred/advertised way to test is @pytest.mark.asyncio async def test_something() and (perhaps) direct use of event_loop is rare?