patch 9.0.0418: manually deleting temp test files

Problem:    Manually deleting temp test files.
Solution:   Use the 'D' flag of writefile() and mkdir().

src/version.c

@@ -703,6 +703,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    418,
 /**/
     417,
 /**/