VOLUME used in Dockerfile prevents downstream modification of /opt/tyk-gateway/

[nicodeceulaer]

Docker does not allow changes to a VOLUME'd directory after the VOLUME command in a Dockerfile.
This includes other Dockerfiles that inherit upon a base dockerfile.

This dockerfile has a VOLUME mount of /opt/tyk-gateway/

But this causes problems for me (I'm adding other files into /opt/tyk-gateway/ in my Dockerfile)

Links to relevant discussion on docker github page:
moby/moby#3639