Failing image_build

Hi Remko,

We have encountered this problem over the last few weeks - it is due to an external dependency on rdfjson-lib. There is a quick fix here: Error during Environment creation - #10 by ralf.grubenmann where you can modify the Dockerfile slightly. It should solve the problem for that repository. Hopefully the fix is small enough to propagate to the other repos where it is erroring.

Let us know if that works!