Merge pull request #193 from bcaller/py37

Test running pyt in a python 3.7 env

Author: KevinHock

.travis.yml

@@ -1,6 +1,8 @@
 language: python
+dist: xenial
 python:
  - "3.6"
+ - "3.7"
 install:
  - pip install codeclimate-test-reporter 'coverage>=4.0,<4.4' flake8
 before_script:

tox.ini

@@ -1,12 +1,11 @@
 [tox]
-envlist = py36,cover,lint
+envlist = py36,py37,cover,lint
 
 [testenv]
 commands =
  python -m tests
 
 [testenv:cover]
-whitelist_externals = coverage
 deps =
  coverage>=4.0,<4.4
 commands =