[#7] Move installation of gfortran and add sudo

Author: meatballs

.travis.yml

@@ -5,10 +5,10 @@ python:
 before_install:
   - export DISPLAY=:99.0
   - sh -e /etc/init.d/xvfb start
+  - sudo apt-get install gfortran
 install:
   - pip install -r requirements.txt
   - pip install pytest
-  - apt-get install gfortran
   - git clone https://github.com/Axelrod-Python/TourExec.git /tmp/TourExec
   - cd /tmp/TourExec
   - make install