Enable Travis CI

.travis.yml

@@ -0,0 +1,18 @@
+language: python
+
+matrix:
+    include:
+        - python: 2.6 # these are just to make travis's UI a bit prettier
+          env: TOXENV=py26
+        - python: 2.7
+          env: TOXENV=py27
+        - python: 3.3
+          env: TOXENV=py33
+        - python: 3.4
+          env: TOXENV=py34
+        - python: 3.5
+          env: TOXENV=py35
+        - python: nightly
+          env: TOXENV=py36
+        - python: pypy
+          env: TOXENV=pypy

tox.ini

@@ -1,11 +1,19 @@
 [tox]
-envlist = py27, pypy, py34, py35, pypy3
+envlist = py26, py27, pypy, py33, py34, py35, py36, pypy3
+skip_missing_interpreters = True
 
 [testenv]
 commands = {envpython} test_contextlib2.py
 
+[testenv:py26]
+deps = unittest2
+
 [testenv:py27]
 deps = unittest2
 
 [testenv:pypy]
 deps = unittest2
+
+[testenv:pypy3]
+# Known incompatibility: https://bitbucket.org/pypy/pypy/issues/1903
+ignore_outcome = True