Fix ignoreWhitespace mode

[mallorydxw]

assertions/src/HTML.php

Lines 16 to 19 in 18a9bef

	if ($ignoreWhitespace) {
	$out = preg_replace('/>\s+/m', '>', $out);
	$out = preg_replace('/\s+</m', '<', $out);
	}

This is just wrong. We should be able to iterate through the DOM and when we encounter a text node we should remove all leading/trailing whitespace.