Refactor Travis builds

Author: saghul

.travis.yml

@@ -1,17 +1,24 @@
-sudo: false
 language: python
-matrix:
-    include:
-        - python: 2.7
-          env: TOXENV=py27
-        - python: 3.3
-          env: TOXENV=py33
-        - python: 3.4
-          env: TOXENV=py34
-        - python: pypy
-          env: TOXENV=pypy
+sudo: false
+python:
+  - "2.7"
+  - "3.3"
+  - "3.4"
+  - "3.5"
+  # pypy2.7-5.8.0 is broken in Travis
+  - "3.6"
+  - "pypy-5.6.0"
+  - "pypy3.5-5.8.0"
+branches:
+  only:
+    - master
 install:
-    - pip install tox
+  - python -V
+  - python setup.py build_ext --inplace
+  - pip install nose
 script:
-    - tox
-
+  - nosetests -v
+notifications:
+  email:
+    on_success: never
+    on_failure: change