Refactor to get assertTrue

---

As we are also programmers we will soon recognize that there is code duplication in our test script and will factor out the whole printing of pass/fail part to a function that we call assertTrue(). It should receive a true or false value and it will print "pass" or "fail" accordingly.

examples/php/intro/t04.php

<?php

require_once(dirname(__FILE__) . '/../includes/mylib.php');

assertTrue(add(1,1)   == 2);
assertTrue(add(2,2)   == 4);
assertTrue(add(1,1,1) == 3);


function assertTrue($condition) {
    print ($condition ? 'pass' : 'fail') . '<br>';
}

?>

Result:

pass
pass
fail

As in every refactoring the functionality and the output should remain the same, just the implementation improves. (Hopefully)