test_management_commands: Use subTest with help tests.
test_management_commands: Use subTest with help tests.

We remove the print statement, and instead use
subTest to improve debuggability.

showell/zulip,shubhamdhama/zulip,synicalsyntax/zulip,shubhamdhama/zulip,andersk/zulip,punchagan/zulip,rht/zulip,andersk/zulip,timabbott/zulip,showell/zulip,kou/zulip,punchagan/zulip,timabbott/zulip,andersk/zulip,showell/zulip,synicalsyntax/zulip,shubhamdhama/zulip,showell/zulip,hackerkid/zulip,zulip/zulip,kou/zulip,shubhamdhama/zulip,punchagan/zulip,timabbott/zulip,eeshangarg/zulip,hackerkid/zulip,rht/zulip,eeshangarg/zulip,brainwane/zulip,punchagan/zulip,showell/zulip,synicalsyntax/zulip,hackerkid/zulip,eeshangarg/zulip,rht/zulip,zulip/zulip,kou/zulip,eeshangarg/zulip,rht/zulip,zulip/zulip,hackerkid/zulip,timabbott/zulip,shubhamdhama/zulip,timabbott/zulip,andersk/zulip,kou/zulip,eeshangarg/zulip,andersk/zulip,brainwane/zulip,brainwane/zulip,brainwane/zulip,rht/zulip,zulip/zulip,shubhamdhama/zulip,synicalsyntax/zulip,zulip/zulip,punchagan/zulip,hackerkid/zulip,kou/zulip,brainwane/zulip,eeshangarg/zulip,eeshangarg/zulip,rht/zulip,zulip/zulip,synicalsyntax/zulip,kou/zulip,synicalsyntax/zulip,kou/zulip,showell/zulip,punchagan/zulip,showell/zulip,hackerkid/zulip,brainwane/zulip,andersk/zulip,shubhamdhama/zulip,andersk/zulip,brainwane/zulip,hackerkid/zulip,zulip/zulip,synicalsyntax/zulip,timabbott/zulip,punchagan/zulip,rht/zulip,timabbott/zulip