Tell Travis to use python 3.3 VirtualEnv instead of system python.

Should fix travis failures when installing get-pip.

.travis.yml

@@ -2,16 +2,16 @@
 #   http://lint.travis-ci.org/
 
 
-language: c
-#python:
-#    - 3.3
+language: python
+python:
+    - 3.3
 #    - 3.4
 
 install:
     - git clone --depth=50 --branch=maintenance/gramps42 git://github.com/gramps-project/gramps.git gramps-project/gramps
-    - cd gramps-project/gramps 
+    - cd gramps-project/gramps
     - time sudo apt-get update
-    - travis_retry sudo apt-get install gir1.2-pango gir1.2-gtk xdg-utils librsvg2-common libglib2.0-dev intltool 
+    - travis_retry sudo apt-get install gir1.2-pango gir1.2-gtk xdg-utils librsvg2-common libglib2.0-dev intltool
     - travis_retry sudo apt-get install python3-gobject python3-gi python3-cairo python3-gi-cairo python3-bsddb3 python3-dev python3-nose
 
     - travis_retry curl https://bootstrap.pypa.io/get-pip.py | sudo python3