Merge branch 'master' into fix-qt-keycodes

* master:
  fix pip install command for PIL
  the new version of pip complains for PIL because it is an extenral repo and the checksum cannot be verified

.travis.yml

@@ -15,7 +15,7 @@ install:
   - pip install cython
   - sudo apt-get install python-numpy
   - sudo apt-get install swig
-  - pip install PIL
+  - pip install PIL --allow-external PIL --allow-unverified PIL
   - pip install pyparsing
   # Test against the current master of traits and traitsui
   - pip install git+http://github.com/enthought/traits.git#egg=traits