Print out release environments variables

What does this MR do and why?

Print out the release environments variables that are passed to the triggered pipeline, so it is easier to debug without downloading the artifact.

Example

An example of the expected output:

ENVIRONMENT=16-10-stable
VERSIONS={"gitaly":"16-10-stable-42668c3d","registry":"16-10-stable-42668c3d","kas":"16-10-stable-42668c3d","mailroom":"16-10-stable-42668c3d","pages":"16-10-stable-42668c3d","gitlab":"16-10-stable-42668c3d","shell":"16-10-stable-42668c3d","praefect":"16-10-stable-42668c3d"}