.travis.yml modification (no email notifications, add folding)

.travis.yml

@@ -1,10 +1,14 @@
 language: python
+notifications:
+  email: false
 python:
   - "3.5"
   - "3.6"
   - "3.5-dev" # 3.5 development branch
   - "3.6-dev" # 3.6 development branch
 # command to install dependencies
-install: "pip install -r requirements.txt"
+install:
+  - "pip install -r requirements.txt"
+  - "pip install pytest-travis-fold"
 # command to run tests
 script: pytest