Remove `loop` params

[Olegt0rr]

Application developers should typically use the high-level asyncio functions, such as asyncio.run(), and should rarely need to reference the loop object or call its methods

[mosquito]

@Olegt0rr thanks for this PR, but I'm afraid you overdid it a bit. The fact is that now the main supported versions of python in this project are 3.7, 3.8, 3.9 and 3.10, and only in the latter the support for the loop argument has beed dropped.

Your first commit was limited only to the fact that you removed this argument from the examples, which is good, I agree with this, but in order to remove this from the entire public API, I will have to bump the major version.

[Olegt0rr]

Agree :) The second commit reverted

[Olegt0rr]

If we consider docs then there is also loop parameter here https://github.com/mosquito/aio-pika/blame/master/docs/source/rabbitmq-tutorial/2-work-queues.rst#L162 and here https://github.com/mosquito/aio-pika/blob/master/docs/source/rabbitmq-tutorial/examples/6-rpc/rpc_client.py.

Now fixed

[decaz]

@mosquito did we dropped support of 3.6? If no then @Olegt0rr should left the usage of asyncio.get_event_loop.

[mosquito]

@decaz yep https://github.com/mosquito/aio-pika/blob/master/setup.py#L32

[decaz]

@mosquito I asked because we still have "Python 3.6+ compatible." in README.

[mosquito]

@decaz fixed

[coveralls]

coverage: 88.402%. remained the same when pulling ff3cc46846d3af86207041150d3da220cb4e2f63 on Olegt0rr:hide-loop into 478b3e9f2bba21c0918195eef94614c6cf39a52d on mosquito:master.