declare Python 3.7 support; run Python 3.7 tests

Author: kmike

.travis.yml

@@ -18,6 +18,10 @@ matrix:
       env: TOXENV=py35
     - python: 3.6
       env: TOXENV=py36
+    - python: 3.7
+      env: TOXENV=py37
+      dist: xenial
+      sudo: true
 install:
   - |
       if [ "$TOXENV" = "pypy" ]; then

setup.py

@@ -72,6 +72,7 @@ def has_environment_marker_platform_impl_support():
         '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',
     ],

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py27, py34, py35, py36, pypy, pypy3
+envlist = py27, py34, py35, py36, py37, pypy, pypy3
 
 [testenv]
 deps =