Update Travis CI file to accept Pipfile

JavierLuna · JavierLuna · commit 9716cf13c158 · 2018-12-26T21:17:01.000+01:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,7 +1,10 @@
 language: python
 python:
     - '3.6'
+    - '3.7-dev'
 install:
+  - pip install pipenv
+  - pipenv install --dev
   - pip install -U tox coveralls
 
 script:
