Revert "test: added -D option to subunitrun"

This reverts commit ac0bba2ea18e2e9ac578a333a3b260951e4c976e.

"python -m subunit.run" is the preferred way of running tests to
generate subunit. I also don't want to move too far away from
the standard test running infrastructure for python so that
other test runners (nosetests, trial, tribunal, ...) can be used with
Samba code.

source4/scripting/bin/subunitrun

@@ -56,8 +56,6 @@ credopts = options.CredentialsOptions(parser)
 sambaopts = options.SambaOptions(parser)
 parser.add_option_group(credopts)
 parser.add_option_group(sambaopts)
-parser.add_option('-D', '--directory', dest='directory', default=None,
-                  help='set test directory')
 try:
     from subunit.run import TestProgram
 except ImportError:
@@ -74,8 +72,5 @@ samba.tests.cmdline_credentials = credopts.get_credentials(lp)
 if getattr(opts, "listtests", False):
     args.insert(0, "--list")
 
-if opts.directory:
-    sys.path.append(opts.directory)
-
 runner = SubunitTestRunner()
 program = TestProgram(module=None, argv=[sys.argv[0]] + args, testRunner=runner)