procps contains process CLI tools like /bin/ps etc. It is currently
unclear why these must be installed. But in the past it was important
enough to keep it in the GOSS tests, which checks for the installation
of this package.

The section "Test SonarQube Dogu" was a bit ambiguous. After upgrading
the build-lib nothing worked while with the old build-lib and correctly
named Jenkins credentials the build on the /master branch worked
out-of-the-box.

This commit amends some of the ambiguity of the docs and adds context.