Fix curl command line in client script
Currently it is generating a file named `--write-out` every time it
runs.
@@ -9,6 +9,6 @@ curl \
--request POST \
--data '{"lat":1,"lon":2}' \
--silent \
- --output \
- --write-out \
+ --output /dev/null \
+ --write-out '%{http_code}\n%{content_type}\n' \
localhost:8080/invoke
