Use fast_finish and allow_failures

Author: sfischer13

.travis.yml

@@ -9,6 +9,11 @@ python:
   - 3.6
   - nightly
 
+matrix:
+  fast_finish: true
+  allow_failures:
+    - python: nightly
+
 install:
   - pip install .
   - pip install -r requirements.txt