Merge pull request #849 from alphagov/dependabot/bundler/net-imap-0.6.4

Bump net-imap from 0.6.3 to 0.6.4

Author: KludgeKML

Gemfile.lock

@@ -245,7 +245,7 @@ GEM
     multi_json (1.19.1)
     multi_xml (0.8.1)
       bigdecimal (>= 3.1, < 5)
-    net-imap (0.6.3)
+    net-imap (0.6.4)
       date
       net-protocol
     net-pop (0.1.2)