Axrj/ci fix (#690)

* use python2 instead of py3 default installation for nwjs test

Author: axrj

.travis.yml

@@ -58,7 +58,10 @@ matrix:
           sources: [ 'ubuntu-toolchain-r-test' ]
           packages: ['xvfb','libasound2','libx11-6','libglib2.0-0','libgtk2.0-0','libatk1.0-0','libgdk-pixbuf2.0-0','libcairo2','libfreetype6','libfontconfig1','libxcomposite1','libasound2','libxdamage1','libxext6','libxfixes3','libnss3','libnspr4','libgconf-2-4','libexpat1','libdbus-1-3','libudev1']
       script:
-        # test node-webkit usage
+        # use python2.x since it breaks with python3.x which is the default installation 
+        # https://github.com/nwjs/node/issues/46
+        - ln -s /usr/bin/python2 ~/bin/python
+        - ln -s /usr/bin/python2-config ~/bin/python-config
         - ./scripts/test-node-webkit.sh
 
 install: