Closes #606: Add expected standart output

Signed-off-by: Marcela Bonell <[email protected]>

test/tests/php-hello-world/expected-std-out.txt

@@ -0,0 +1 @@
+Hello World!

test/tests/php-hello-world/index.php

@@ -1,2 +1 @@
-<?php echo "Hello World!"; ?> 
-
+<?php echo "Hello World!"; ?>