Add Python 3.7 support to Travis and Tox

.travis.yml

@@ -12,6 +12,11 @@ matrix:
     - python: 3.6
       env:
       - TOX_ENV=py36
+    - python: 3.7
+      sudo: true
+      dist: xenial
+      env:
+      - TOX_ENV=py37
 addons:
   apt_packages:
     - pandoc

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py{27,34,35,36},docs,flake8
+envlist = py{27,34,35,36,37},docs,flake8
 
 [testenv]
 basepython =
@@ -7,6 +7,7 @@ basepython =
     py34: python3.4
     py35: python3.5
     py36: python3.6
+    py37: python3.7
 passenv = *
 usedevelop=True
 deps =