Add python 3.6 to travis config

Author: derek73

.travis.yml

@@ -6,6 +6,7 @@ python:
   - "3.3"
   - "3.4"
   - "3.5"
+  - "3.6"
 # command to install dependencies
 install: 
   - if [[ $TRAVIS_PYTHON_VERSION == '2.6' ]]; then pip install --use-mirrors unittest2; fi