Add Python 3.5 to tox.ini and .travis.yml

.travis.yml

@@ -1,18 +1,30 @@
 language: python
 
 sudo: false
-env:
-    - TOXENV=cover
-    - TOXENV=cover3
-    - TOXENV=py26
-    - TOXENV=py27
-    - TOXENV=py32
-    - TOXENV=py33
-    - TOXENV=py34
-    - TOXENV=pypy
+
+matrix:
+    include:
+        - python: 2.7
+          env: TOXENV=cover
+        - python: 3.5
+          env: TOXENV=cover3
+        - python: 2.6
+          env: TOXENV=py26
+        - python: 2.7
+          env: TOXENV=py27
+        - python: 3.2
+          env: TOXENV=py32
+        - python: 3.3
+          env: TOXENV=py33
+        - python: 3.4
+          env: TOXENV=py34
+        - python: 3.5
+          env: TOXENV=py35
+        - python: pypy
+          env: TOXENV=pypy
 
 install:
-    - travis_retry pip install tox==1.6.1
+    - travis_retry pip install tox
 
 script:
     - travis_retry tox

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 envlist =
-    cover,cover3,py26,py27,py32,py33,py34,pypy
+    cover,cover3,py26,py27,py32,py33,py34,py35,pypy
 
 [testenv]
 deps =