Merge branch 'ch/new-gpg-drops-rfc-1991'

Recent GPG changes the keyring format and drops support for RFC1991 formatted signatures, breaking our existing tests. * ch/new-gpg-drops-rfc-1991: tests: make comment on GPG keyring match the code tests: squelch noise from GPG machinery set-up tests: replace binary GPG keyrings with ASCII-armored keys tests: skip RFC1991 tests for gnupg 2.1 tests: create gpg homedir on the fly