Use Trusty for all builds except PHP 5.3
Use Trusty for all builds except PHP 5.3

PHP 5.2 and PHP 5.3 are not supported on Travis CI:
"If you need PHP 5.2 or 5.3, please use Precise."

zachborboa/php-curl-class,php-curl-class/php-curl-class,zachborboa/php-curl-class,zachborboa/php-curl-class,php-curl-class/php-curl-class,php-curl-class/php-curl-class