chore(deps): bump mail from 2.9.0 to 2.9.1

Bumps [mail](https://github.com/mikel/mail) from 2.9.0 to 2.9.1.
- [Release notes](https://github.com/mikel/mail/releases)
- [Changelog](https://github.com/mikel/mail/blob/master/CHANGELOG.rdoc)
- [Commits](https://github.com/mikel/mail/compare/2.9.0...2.9.1)

---
updated-dependencies:
- dependency-name: mail
  dependency-version: 2.9.1
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile.lock

@@ -196,7 +196,7 @@ GEM
     loofah (2.25.1)
       crass (~> 1.0.2)
       nokogiri (>= 1.12.0)
-    mail (2.9.0)
+    mail (2.9.1)
       logger
       mini_mime (>= 0.1.1)
       net-imap
@@ -211,12 +211,12 @@ GEM
     mysql2 (0.5.6)
     net-http (0.4.1)
       uri
-    net-imap (0.6.4)
+    net-imap (0.6.6)
       date
       net-protocol
     net-pop (0.1.2)
       net-protocol
-    net-protocol (0.2.2)
+    net-protocol (0.3.0)
       timeout
     net-smtp (0.5.1)
       net-protocol