language: python
python:
 - "2.7"
 - "3.4"
 - "3.5"
 - "3.6"
script:
 - python setup.py test

language: python
python:
 - "2.7"
 - "3.4"
 - "3.5"
 - "3.6"
# Hack for Python 3.7; remove when Travis correctly supports it.
matrix:
  include:
    - python: 3.7
      dist: xenial
      sudo: true
script:
 - python setup.py test

Add Python 3.7 to Travis
Add Python 3.7 to Travis

Python 3.7 is the current stable version. It's useful to test our code
against it.

Unfortunately, Travis only allows testing against it via a hack, see

https://github.com/travis-ci/travis-ci/issues/9815
https://github.com/travis-ci/travis-ci/issues/9069#issuecomment-425720905
