I noticed in your setup.py file that you have a requirement for Python version >= 3.5, but you do not have a python_requires keyword, and you have the Python 3.4 in your trove classifiers.

I suggest adding python_requires=">= 3.5" to your setup() invocation and removing Python 3.4 from your trove classifiers.

(Adding this because it's relevant for python_requires, not because I have any evidence you don't already know it). When uploading your distributions, make sure to use twine, instead of setup.py upload, since the latter is deprecated and some versions of setuptools have bugs that will cause problems for some users.