Skip test on php 5.3
Trying to fix: PHP Fatal error:  Call to a member function getCurrency() on a non-object in /home/travis/build/piwik/piwik/plugins/Live/API.php on line 554
https://travis-ci.org/piwik/piwik/jobs/22318726
Note: this should not happen really and I'm puzzled... especially as it works on other PHP versions...