Merge pull request #79 from SylvainDe/master

Add most recent Python versions in Travis CI

Author: repeatedly

.travis.yml

@@ -6,6 +6,10 @@ python:
   - "3.3"
   - "3.4"
   - "3.5"
+  - "3.6"
+  - "3.6-dev"
+  - "3.7-dev"
+  - "nightly"
 # command to install dependencies, e.g. pip install -r requirements.txt --use-mirrors
 install:
     - "pip install -e ."