2017-10-10: adjust header of doctests-test.w

adjust header of doctests-test.w

diff --git a/examples/doctests-test.w b/examples/doctests-test.w
--- a/examples/doctests-test.w
+++ b/examples/doctests-test.w
@@ -1,7 +1,7 @@
 #!/usr/bin/env sh
 # -*- wisp -*-
-guile -L $(dirname $(dirname $(realpath "$0"))) -c '(import (wisp-scheme) (language wisp spec))'
-exec guile -L $(dirname $(dirname $(realpath "$0"))) --language=wisp -e '(@@ (examples doctests-test) main)' -s "$0" "$@"
+guile -L $(dirname $(dirname $(realpath "$0"))) -c '(import (language wisp spec))'
+exec guile -L $(dirname $(dirname $(realpath "$0"))) -x .w --language=wisp -e '(@@ (examples doctests-test) main)' -s "$0" "$@"
 ; !#
 
 define-module : examples doctests-test