Sigh, travis install needs sudo for apt-get

.travis.yml

@@ -4,7 +4,7 @@ python:
   - "2.7"
 install:
   - pip install -r python/test_requirements.txt --use-mirrors
-  - apt-get install mono-devel
+  - sudo apt-get install mono-devel
 compiler:
   - gcc
   - clang