Don't require sudo for travis builds

Should make builds faster as they run on cheap containers instead of bare instances.

Author: jbbarth

.travis.yml

@@ -2,6 +2,9 @@ language: python
 python:
  - "2.7"
 
+# run on container-based infrastructure
+sudo: false
+
 # command to install dependencies
 install:
  - pip install -UI pip==7.1.2