Use setuptools_scm to automate versioning

[wbarnha]

Closes #406.

Still not done yet because I need the version in https://github.com/faust-streaming/faust/blob/master/docs/includes/tags.txt to automatically update.

I'm also removing the publish script since we're standardizing releases through Github Releases from hereon.

Before merging this, I'd like to use setuptools_scm in a non-deprecated way as well, by having it outside of setup.py and in setup.cfg.

[wbarnha]

Apparently usage of setuptools_scm in setup.py and setup.cfg is deprecated, we'd have to make a pyproject.toml file.

[wbarnha]

Should probably remove bumpversion as well.

[wbarnha]

https://wbarnha.github.io/faust/introduction.html looks good. Just need to make sure we issue a release shortly after merging this to ensure PyPi info is correct.

[wbarnha]

Before merging this, I should verify releases to PyPi work properly.

[wbarnha]

PyPi test release successful. LGTM.

[codecov-commenter]

Codecov Report

Base: 94.02% // Head: 92.91% // Decreases project coverage by -1.11% ⚠️

Coverage data is based on head (b1fe48b) compared to base (90be0cc).
Patch coverage: 100.00% of modified lines in pull request are covered.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #407      +/-   ##
==========================================
- Coverage   94.02%   92.91%   -1.12%     
==========================================
  Files         102      102              
  Lines       11076    11076              
  Branches     1298     1258      -40     
==========================================
- Hits        10414    10291     -123     
- Misses        583      705     +122     
- Partials       79       80       +1     

Impacted Files	Coverage Δ
faust/__init__.py	100.00% <100.00%> (ø)
faust/windows.py	56.89% <0.00%> (-43.11%)	⬇️
faust/streams.py	72.26% <0.00%> (-15.76%)	⬇️
faust/transport/conductor.py	98.58% <0.00%> (-1.42%)	⬇️
faust/models/typing.py	94.36% <0.00%> (-0.94%)	⬇️
faust/livecheck/patches/aiohttp.py	100.00% <0.00%> (ø)

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