Specify maximum python versions for dependencies

[cage433]

The dependencies 'typing' and 'singledispatch' are only required for Python < 3.5

I had trouble building an venv with Python 3.8, it complained about those packages, so I followed the instructions at https://pypi.org/project/typing/

[codecov[bot]]

Codecov Report

Merging #27 (c0069d9) into master (5e52c13) will not change coverage. The diff coverage is n/a.

@@           Coverage Diff           @@
##           master      #27   +/-   ##
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  Coverage   98.50%   98.50%           
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  Files          19       19           
  Lines        1200     1200           
  Branches      118      118           
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  Hits         1182     1182           
  Misses         13       13           
  Partials        5        5           

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[ingolemo]

Pythons lower than 3.6 are now unsupported, so these dependencies should just be removed.

Don't change the version number. Not every commit warrants a whole new release.

[cage433]

Is a version bump not a good idea? I'm as far as it can get from a Python expert, so I could well be wrong. I saw this issue when trying to build a 3.8 venv with your library as a new dependency. I deployed your whl to our local artifactory, but failed to build the venv due to these dependences. I fixed it temporarily by making the above changes, including the version bump, rebuilding the wheel and deploying to our artifactory. The 1.0.1 dependency then worked just fine

Possibly our circumstances are unique, or there was an easier workaround I could have done - as I say this not my area of expertise

[ingolemo]

Version numbers only change when there's a release, and they do so in a dedicated commit. A version bump now would require 1.1.0, not 1.0.1, due to changes in other commits.

I don't know why your virtual environment setup was failing. These modules still work fine on python 3.8 and I am able to install to a venv on my own system. Sounds like artifactory is super fastidious.