Reformat travis.yml and turn off email notifications (#4159)

.travis.yml

 language: python
 
 python:
-  - "3.5"
+    - "3.5"
 
 sudo: false
 
@@ -20,20 +20,16 @@ env:
     - TOX_ENV=py35-django110
     - TOX_ENV=py34-django110
 
-
-
 matrix:
-  allow_failures:
-    - env: TOX_ENV=py27-django110
-    - env: TOX_ENV=py34-django110
-    - env: TOX_ENV=py35-django110
-
-
-  fast_finish: true
+    allow_failures:
+        - env: TOX_ENV=py27-django110
+        - env: TOX_ENV=py34-django110
+        - env: TOX_ENV=py35-django110
+    fast_finish: true
 
 install:
-  # Virtualenv < 14 is required to keep the Python 3.2 builds running.
-  - pip install tox "virtualenv<14"
+    # Virtualenv < 14 is required to keep the Python 3.2 builds running.
+    - pip install tox "virtualenv<14"
 
 script:
     - tox -e $TOX_ENV
@@ -41,3 +37,6 @@ script:
 after_success:
     - pip install codecov
     - codecov -e TOX_ENV
+
+notifications:
+    email: false