Updates needed for recent trio versions (0.17.0 current as of this writing)

[mikenerone]

There have been a number of deprecations/removals in trio since trio-amqp was last updated:

• open_cancel_scope() deprecated
• Event.clear() deprecated
• Python 3.5 support removed
• trio.hazmat renamed to trio.lowlevel (also as Updates needed for recent trio versions (0.17.0 current as of this writing) #11)

I will submit a PR shortly to address these changes.

There are also some existing similar updates in master (at least the removal of trio.Queue) that have yet to be released. As a result, the current release of trio-amqp is currently only compatible with trio<=0.8.0 (0.17.0 is current). Please make a new release as soon as possible. There's been no movement on releasing https://github.com/M-o-a-T/asyncamqp as mentioned in #8, and it sounds like you intend to instead merge that back into trio-amqp as discussed in #9, but the situation right now is that there is no working, released AMQP client library for recent versions of trio.

[mikenerone]

Since the recent reset to match https://github.com/M-o-a-T/asyncamqp, which is anyio-based, means that this code no longer uses trio interfaces directly, this issue is effectively addressed.

@smurfix Which of the two repos would you say is the one I should dep going forward? Also, are you planning a PyPI release soon so that I don't have to use a git URL dep? :)