always update setuptools and pip first to avoid broken travis

RonnyPfannschmidt · RonnyPfannschmidt · commit 9a2430ffebf5 · 2017-11-24T07:50:39.000+01:00
diff --git a/.travis.yml b/.travis.yml
@@ -31,6 +31,7 @@ matrix:
       env: TOXENV=benchmark
 
 install:
+  - pip install -U setuptools pip
   - pip install -U tox
 
 script:
