Merge pull request #40 from thc202/travis-ci-py-3.x

Add newer Python versions to Travis CI

Author: kingthorin

.travis.yml

@@ -1,8 +1,10 @@
+dist: xenial
 sudo: false
 language: python
 python:
   - '2.7'
-  - '3.4'
+  - '3.6'
+  - '3.7'
 install:
   - pip install -U --force setuptools pip
   - ./setup.py develop