Fix travis

.travis.yml

@@ -22,7 +22,7 @@ before_install:
 before_script:
   - sudo rm -rf /etc/mysql/
   - sudo bash -c 'echo example.com > /etc/hostname'
-  - sudo apt-get -qq purge mysql* graphviz*
+  - sudo apt-get -qq purge mysql* graphviz* redis*
   - sudo apt-get -qq autoremove --purge
 
 script: