Adapted test to avoid using '-no_pkgs' to avoid getting unnecessary
errors due to missing pacakges that the script knows how to install.
The original idea was that tests would start very minimalistic, e.g.
having earlier tests do as little as possible with various '-no_this'
and '-no_that' options (e.g. 'no_pkgs'). However, now that we have
test groups and each test group should be exeutable indepdently with
no dependency on order of tests done, this had to change. Now each
test will try to install needed packages.