Fix deprecation warning for PyPI description check

.travis.yml

@@ -51,7 +51,7 @@ matrix:
       stage: docs
       env: TOXENV=docs
     - python: "3.7"
-      env: TOXENV=readme
+      env: TOXENV=pypi-description
     - python: "3.7"
       env: TOXENV=changelog
 

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = typing,lint,py27,py34,py35,py36,py37,pypy,pypy3,manifest,docs,readme,changelog,coverage-report
+envlist = typing,lint,py27,py34,py35,py36,py37,pypy,pypy3,manifest,docs,pypi-description,changelog,coverage-report
 
 
 [testenv]
@@ -61,11 +61,15 @@ skip_install = true
 commands = check-manifest
 
 
-[testenv:readme]
+[testenv:pypi-description]
 basepython = python3.7
-deps = readme_renderer
 skip_install = true
-commands = python setup.py check -r -s
+deps =
+    twine
+    pip >= 18.0.0
+commands =
+    pip wheel -w {envtmpdir}/build --no-deps .
+    twine check {envtmpdir}/build/*
 
 
 [testenv:changelog]