Drop upstream formulas test
    
    Test is useless, we are using downstream mirrors, sometimes forks, of
    the formulas which are already tested as part of "show_highstate".
    Additionally, the upstream formula test fails if we use downstream patches
    containing files not available in the upstream repository, as state
    includes fail to find them.
    As a replacement for this, a new test was introduced in salt-formulas-git,
    which correctly tests the downstream formulas when they get updated.
    
    Signed-off-by: Georg Pfuetzenreuter <mail@georg-pfuetzenreuter.net>