Support Python 3.7, test with Python 3.8 dev

Author: stefankoegl

.travis.yml

@@ -1,11 +1,13 @@
+dist: xenial
 language: python
 python:
 - '2.7'
 - '3.4'
 - '3.5'
 - '3.6'
-- 3.6-dev
+- '3.7'
 - 3.7-dev
+- 3.8-dev
 - nightly
 - pypy
 - pypy3

setup.py

@@ -59,6 +59,7 @@
     'Programming Language :: Python :: 3.4',
     'Programming Language :: Python :: 3.5',
     'Programming Language :: Python :: 3.6',
+    'Programming Language :: Python :: 3.7',
     'Programming Language :: Python :: Implementation :: CPython',
     'Programming Language :: Python :: Implementation :: PyPy',
     'Topic :: Software Development :: Libraries',