add get_structuring_element.phpt

Signed-off-by: MaleicAcid <CS_MaleicAcid@163.com>

Author: MaleicAcid

tests/get_structuring_element.phpt

@@ -10,6 +10,7 @@ $morph_elem = 2;
 $morph_size = 3;
 $element = getStructuringElement( $morph_elem, new Size( 2*$morph_size + 1, 2*$morph_size+1 ), new Point( $morph_size, $morph_size ));
 
+
 var_dump($element);
 $element->print();