Run tests against a few more pythonv versions.

.travis.yml

@@ -12,6 +12,14 @@ matrix:
       env: TEST_REQUIRE="gevent greenlet geventhttpclient fastimport"
     - python: "3.5"
       env: TEST_REQUIRE="gevent greenlet geventhttpclient fastimport"
+    - python: "3.5-dev"
+      env: TEST_REQUIRE="gevent greenlet geventhttpclient fastimport"
+    - python: "3.6"
+      env: TEST_REQUIRE="gevent greenlet geventhttpclient fastimport"
+    - python: "3.6-dev"
+      env: TEST_REQUIRE="gevent greenlet geventhttpclient fastimport"
+    - python: "3.7-dev"
+      env: TEST_REQUIRE="gevent greenlet geventhttpclient fastimport"
 cache:
   directories:
     - $HOME/.cache/pip

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 downloadcache = {toxworkdir}/cache/
-envlist = py27, pypy, py27-noext, pypy-noext, py34, py34-noext, py35, py35-noext
+envlist = py27, pypy, py27-noext, pypy-noext, py34, py34-noext, py35, py35-noext, py36, py36-noext
 
 [testenv]
 
@@ -19,3 +19,6 @@ commands = make check-noextensions
 
 [testenv:py35-noext]
 commands = make check-noextensions
+
+[testenv:py36-noext]
+commands = make check-noextensions