PR: Migrate package to use asyncio, remove Python 2.7 support

[andfoy]

This PR enables this package to use asyncio constructs by default, all the functions were migrated to use async/await syntax and ThreadPoolExecutor was removed and replaced by asyncio.tasks

[poppyschmo]

@andfoy

You beat me to it! If you catch any grief over the breaking change, it might be worth considering an alternate layout with all the asyncio analogs couched in a subpackage. Hope this PR gains some traction.

[andfoy]

Hi @poppyschmo, thanks for your input on this one, right now we're stuck until @ccordoba12 obtains write permissions on this repo

[ccordoba12]

@uschi2000, I forgot to mention we have here the same problem we had on python-language-server. So could you remove the Required checks on this repo so we can migrate our tests to Github Actions?

[ccordoba12]

Pinging @uschi2000 about this one again. Sorry to bother you again, please see my comment above. That's the last blocker before we can move to Python 3 and better maintain this project.

[uschi2000]

@delta003@jroitgrund could you please take care of the python-language-server CI setup, please?

[delta003]

@ccordoba12 Removed required

[ccordoba12]

@delta003, thanks a lot for your help!

[delta003]

@andfoy I can't push to your fork to fix these tests, it should be quick, can you fix it?

[andfoy]

Hi @delta003, this PR brakes compatibility with the python-language-server, since we don't have a PR ready there. I don't know what @ccordoba12 thinks about creating a release as the last version that supports python 2.7 and include this one on the next one

[ccordoba12]

I agree. We need to leave this one open until a PR that uses asyncio is ready on python-language-server.

[rchl]

FYI: asyncio was introduced in v3.4 so this will not only break compatibility with PY2 by also <3.4.