expired sibkey

This may be related to #1686. After updating keybase today, all commands fail with `expired sibkey: ...`. The key I use for keybase does not expire until 2017, however I am unable to check whether keybase.io knows about this or if it has an earlier expiration date.

(As an aside, perhaps you could reconsider the term 'sibkey' as it looks too much like a typo of 'subkey'?)

Start by reproducing the failure after updating keybase, then compare the reported expiration with issue #1686 and the key's status on keybase.io. Done means the affected key is accepted and keybase commands work without the “expired sibkey” error.

Written by the indexing model from the issue text.