update ci config

.travis.yml

@@ -1,5 +1,3 @@
-sudo: false
-
 language: php
 php:
   - '5.5'
@@ -15,9 +13,12 @@ cache:
     - vendor
     - $HOME/.composer/cache
 
+before_install:
+  - sudo apt-get -qq update
+  - sudo apt-get install -y p7zip-full
+  - sudo apt-get install -y zipalign
+
 before_script:
-  - sudo apt-get install p7zip-full -y
-  - sudo apt-get install zipalign -y
   - composer install
 
 script: