Bump net-imap from 0.3.6 to 0.3.7

Bumps [net-imap](https://github.com/ruby/net-imap) from 0.3.6 to 0.3.7.
- [Release notes](https://github.com/ruby/net-imap/releases)
- [Commits](ruby/net-imap@v0.3.6...v0.3.7)

---
updated-dependencies:
- dependency-name: net-imap
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Gemfile.lock

@@ -107,7 +107,7 @@ GEM
     mini_portile2 (2.8.2)
     minitest (5.18.1)
     msgpack (1.7.1)
-    net-imap (0.3.6)
+    net-imap (0.3.7)
       date
       net-protocol
     net-pop (0.1.2)