Upgrade wheel to be on the safe side

It is used for virtualenvwrapper install and we also upgrade it in AppVeyor.
sambrightman · Oct 6, 2020 · d15f237 · d15f237
1 parent 83d3b9b
commit d15f237
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/.travis.yml b/.travis.yml
@@ -11,7 +11,7 @@ python:
   - "pypy"
   - "pypy3"
 before_install:
-  - pip install -U pip setuptools virtualenvwrapper
+  - pip install -U pip setuptools wheel virtualenvwrapper
   - source virtualenvwrapper.sh
   - wipeenv
 install: