ftests: Add a test to create a systemd scope via cgcreate

ftests: Add a test to create a systemd scope via cgcreate

Add a test to create a systemd scope via the cgcreate command
line tool.

-----------------------------------------------------------------
Test Results:
        Run Date:                          Apr 05 01:35:43
        Passed:                                  1 test(s)
        Skipped:                                 0 test(s)
        Failed:                                  0 test(s)
-----------------------------------------------------------------
Timing Results:
        Test                                  Time (sec)
        ------------------------------------------------
        setup                                       0.00
        078-sudo-cgcreate_systemd_scope.py          5.03
        teardown                                    0.00
        ------------------------------------------------
        Total Run Time                              5.03

Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>
Reviewed-by: Kamalesh Babulal <kamalesh.babulal@oracle.com>