.gitlab-bundle step should show full errors if it failed

Right now if the make .gitlab-bundle step fails, all you see is:

@dimitrieh ran into this today, and once I told him to run cd gitlab; bundle install the error was apparent:

gawk: fatal: cannot use gawk builtin `namespace' as variable name

It looks like gawk v5.0 doesn't work with gpgme: https://trac.macports.org/ticket/58356. Uninstalling gawk solved the problem.

However, we really should save the output somewhere and display it if it fails.