test: drop this directory

test: drop this directory

The remaining contents of the test/ directory are:

  - 2 python example programs that aren't as good as the ones in examples/

  - a test of the deprecated libnm_glib API which isn't as good as the one
    in libnm-glib/

  - A DHCP-related test program that hasn't been relevant since 2005

Let's just kill it all