fix: docker

Dockerfile

@@ -5,4 +5,4 @@ ADD i2-bill-api.tar.gz /app/
 VOLUME [ "/app/etc" ]
 EXPOSE 6166
 WORKDIR /app
-CMD ["/app/i2-bill-api -f etc/i2bill-api.yaml"]
+CMD ["/app/i2-bill-api -f /app/etc/i2bill-api.yaml"]