Merge pull request #117 from ruby/dependabot/bundler/net-imap-0.5.15

Bump net-imap from 0.5.12 to 0.5.15

Author: amatsuda

Gemfile.lock

@@ -162,7 +162,7 @@ GEM
     mini_mime (1.1.5)
     minitest (5.27.0)
     msgpack (1.8.0)
-    net-imap (0.5.12)
+    net-imap (0.5.15)
       date
       net-protocol
     net-pop (0.1.2)