Simplified the Travis configuration

Submodules are already handled by Travis itself, so no need to do it a second time

Author: stof

.travis.yml

@@ -4,7 +4,6 @@ python:
     - "2.7"
 
 install: 
-    - "git submodule update --init"
     - "bash install.sh"
     - "pip install -q -r requirements.txt --use-mirrors"