Merge pull request #133 from jodal/nightly-build

Nightly build

.travis.yml

@@ -1,13 +1,19 @@
 dist: trusty
 sudo: false
 language: python
+
 python:
   - "3.4"
   - "3.5"
   - "3.6"
+  - "nightly"
+matrix:
+  allow_failures:
+    - python: "nightly"
+
 install:
-  - pip install tox-travis
-  - pip install coveralls
+  - pip install coveralls tox-travis
 script:
   - tox
-after_success: coveralls
+after_success:
+  - coveralls