* Fix bug in the output of the ct_verify function
A bug in the CCA transformation was reported on the pqc-forum on 2020-12-10
https://groups.google.com/a/list.nist.gov/g/pqc-forum/c/kSUKzDNc5ME
It was fixed today in 669522db63.
This commit ports that fix to PQClean
* add note to SECURITY.md
* update upstream commit in META.yml
There are schemes, like SABER (#192) that have more than one principal
submitter. Consistency warrants that we turn it into a list for all
schemes and don't do something with allowing either a str or a list:
that would just be very annoying to parse.
Closes#194
