test travis docker system

.travis.yml

@@ -1,5 +1,11 @@
 language: php
 
+sudo: false
+
+cache:
+  directories:
+    - $HOME/.composer/cache
+
 php:
   - 5.4
   - 5.5

tests/TaskwarriorTest.php

@@ -24,7 +24,7 @@ class TaskwarriorTest extends \PHPUnit_Framework_TestCase
         if (file_exists(__DIR__ . '/../task')) {
             $bin = realpath(__DIR__ . '/../task');
         }
-        
+
         $this->taskwarrior = new Taskwarrior(__DIR__ . '/.taskrc', __DIR__ . '/.task', [], $bin);
         $this->taskwarrior->version(); // to initialise
     }