Code review comment for lp:~jtv/launchpad/bug-181368-parallelize

I echo Graham's comments. I found test_getArchitectureTags_contains_no_duplicates and test_getArchitectureTags_counts_any_architecture_enabled_once confusing to read, and we discussed on IRC a way to improve them with a helper method.

I also suspect that test_runApt_reports_failure proves too much. Can you really break this code by naming a distro arch series "--something"? If so, that's its own problem and should be fixed. Or does the error happen because the string "bogus-config" is passed in instead of a real config? In that case, the command might not be run at all, and you'll need another test to show what happens when the command runs and fails.