ensure we are using the latest pip in travis build

ran404 · ran404 · commit 96869d0348b9 · 2017-03-30T22:32:27.000+01:00
diff --git a/.travis.yml b/.travis.yml
@@ -6,6 +6,9 @@ python:
   - "3.6"
 
 install:
-  - pip install plotly
+  - pip install --upgrade pip
+  - pip install --upgrade setuptools wheel
+  - pip install --upgrade pytest
+  - pip install --upgrade plotly
 
 script: pytest
