kbfsgit: comment explaining the bare repo test
kbfsgit: comment explaining the bare repo test

Issue: KBFS-2338

keybase/client,keybase/client,keybase/client,keybase/kbfs,keybase/client,keybase/client,keybase/kbfs,keybase/client,keybase/client,keybase/kbfs,keybase/client,keybase/client,keybase/kbfs,keybase/client,keybase/client,keybase/client