ftests: Add a cgconfigparser test that loads a directory

ftests: Add a cgconfigparser test that loads a directory

Add a cgconfigparser test that loads its configuration files
from a specified directory.

-----------------------------------------------------------------
Test Results:
        Run Date:                          Mar 09 19:49:49
        Passed:                                  1 test(s)
        Skipped:                                 0 test(s)
        Failed:                                  0 test(s)
-----------------------------------------------------------------
Timing Results:
        Test                                    Time (sec)
        ---------------------------------------------------------
        setup                                        21.22
        018-cgconfig-load_dir.py                      0.94
        teardown                                      0.00
        ---------------------------------------------------------
        Total Run Time                               22.16

Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>