Extract wheel from dev-requirements.txt
Instead, install it on demand like twine.
MODIFY
_travis/deploy.sh
_travis/deploy.sh
set -exo pipefail
-python3 -m pip install --upgrade twine
+python3 -m pip install --upgrade twine wheel
python3 setup.py sdist bdist_wheel
python3 -m twine upload dist/* -u $PYPI_USERNAME -p $PYPI_PASSWORD --skip-existing

MODIFY
dev-requirements.txt
dev-requirements.txt
mock==2.0.0
coverage~=4.5
-wheel==0.30.0
tornado==5.1.1
PySocks==1.6.8
pytest-timeout==1.3.3

Extract wheel from dev-requirements.txt

Instead, install it on demand like twine.