Just an FYI for everyone. After wondering why all my extensions suddenly
migrated to the bit bucket in sky, after some digging, searching, browsing,
and tweeting, it's a known issue:
https://discourse.mozilla.org/t/certificate-issue-causing-add-ons-to-be-
disabled-or-fail-to-install/39047
Basically, an "all your extensions are belong to us" situation.