Release script improvements (#6337)

* Add error checking and automatic logging.

* Ignore release dir and logs

* Don't always require PGP card and fix script cmd.

* keep track of default GPG key

* Add PGP card sanity check after offline signature

* fix typo

* I'm tired of pressing y.

* Automate running tools/offline-sigrequest.sh.

* Update comment and make output more readable.

.gitignore

@@ -6,7 +6,8 @@ dist*/
 /venv*/
 /kgs/
 /.tox/
-/releases/
+/releases*/
+/log*
 letsencrypt.log
 certbot.log
 letsencrypt-auto-source/letsencrypt-auto.sig.lzma.base64