Merge pull request #1675 from coderdojo-japan/dependabot/bundler/net-imap-0.5.7

Bump net-imap from 0.5.6 to 0.5.7

Author: yasulab

Gemfile.lock

@@ -288,7 +288,7 @@ GEM
     mutex_m (0.3.0)
     net-http (0.6.0)
       uri
-    net-imap (0.5.6)
+    net-imap (0.5.7)
       date
       net-protocol
     net-pop (0.1.2)