fixed executable location

Signed-off-by: Paul Schultz <pschultz@pobox.com>

Author: schultzp2020

docker/Dockerfile

@@ -11,4 +11,4 @@ RUN go build -o ./main
 
 EXPOSE 8081
 
-CMD [ "/main" , "-p=8081"]
+CMD [ "app/main" , "-p=8081"]