Description of problem:
show skipped pre-upgrade check items as skipped and not failed

Version-Release number of selected component (if applicable):
rubygem-foreman_maintain-0.0.11-1.el7sat.noarch

How reproducible:
Always

Steps to Reproduce:
# foreman-maintain upgrade run --target-version 6.3 --whitelist disk-io 
Running preparation steps required to run the next scenarios
================================================================================
Procedures::Packages::Install: 
Loaded plugins: product-id, search-disabled-repos, subscription-manager
Package hdparm-9.43-5.el7.x86_64 already installed and latest version
No package fio available.
Nothing to do
                                                                      [OK]
--------------------------------------------------------------------------------

nning Checks before upgrading to Satellite 6.3
================================================================================
Check for paused tasks:                                               [OK]
--------------------------------------------------------------------------------
Check whether all services are running using hammer ping:             [OK]
--------------------------------------------------------------------------------
Check for running tasks:                                              [OK]
--------------------------------------------------------------------------------
Check for old tasks in paused/stopped state:                          [OK]
--------------------------------------------------------------------------------
Check for pending tasks which are safe to delete:                     [OK]
--------------------------------------------------------------------------------
Check for tasks in planning state:                                    [OK]
--------------------------------------------------------------------------------
Check for recommended disk speed of pulp, mongodb, pgsql dir.: 
| Finished                                                            [FAIL]    
Slow disk detected /var/lib/pulp mounted on /dev/mapper/rhel_ibm--x3250m4--07-root.
             Actual disk speed: 71 MB/sec
             Expected disk speed: 80 MB/sec.
--------------------------------------------------------------------------------


Actual results:
Check the command that I skipped `disk-io` but the output results showed:
Check for recommended disk speed of pulp, mongodb, pgsql dir.: 
| Finished                                                            [FAIL] 

Expected results:
Check for recommended disk speed of pulp, mongodb, pgsql dir.: 
| Finished                                                            [FAIL/SKIP] 

Additional info: