Convert setup.py to pyproject.toml

[NguoiDungKhongDinhDanh]

pyproject.toml is pretty much the standard nowadays I believe. This, among others, allows us to just run pytest instead of python setup.py pytest which is a handful.

I'm not sure if this breaks anything though.

[NguoiDungKhongDinhDanh]

I don't know why 3.6 is failing. The URL in the log message leads to nowhere.

Edit: Got it; isolated_build = true is needed. 3.6 still fails, however.

[AdamWill]

this is kind of overly aggressive, I think. for my own projects for now I prefer to take a dual approach, providing both pyproject.toml and setup.py such that either can be used alone.

[AdamWill]

also it would probably make most sense to do this after #310 and drop the python 2.x bits from it - this doesn't have a snowball's chance in hell of working with python 2.x, after all.

[AdamWill]

If you compare the 3.6 and 3.7 logs carefully, the 3.6 env just isn't really parsing the deps from pyproject.toml at all, it never tries to pull in requests-oauthlib . That's why the tests fail.

3.6 and 3.7 are EOL now officially, of course. But RH, SUSE and Debian are all still supporting releases with system Python 3.6 or earlier. Debian 8 (Jessie) has 3.4. RHEL (disclaimer: I work for RH) 7 is still in extended support, and its system Python is 2 (ugh). Even if we disregard that, RHEL 8's system Python is 3.6. Best as I can tell for SUSE, SLES 12 is still in support and has system Python 3.4, with a 3.6 package available. (For Ubuntu, 20.04 is the oldest release still in LTS, and it seems to have 3.8).

We don't have to care about ancient LTS distros on our master branch, of course, but...it's considerations like that which make me reluctant to go pyproject.toml-only on an existing project (I probably would on a new one).

[NguoiDungKhongDinhDanh]

Just to be clear: This is not meant to be merged on the fly; I just feel that this needs some place in the PR tab. Until we eventually get to the point where we can ignore anything lower than 3.6, that is.