Use working version.
@@ -58,7 +58,7 @@ install:
- pip install --upgrade "pip==19.1.1"
- pip install --upgrade "setuptools==41.6.0"
- pip install "virtualenv==16.7.7"
- - pip install "tox==3.14.1"
+ - pip install "tox==3.14.0"
- TOX_ENV=py$TRAVIS_PYTHON_VERSION
script:
