Bump net-imap from 0.5.6 to 0.5.7 (#1057)

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Gemfile.lock

@@ -364,7 +364,7 @@ GEM
     msgpack (1.7.5)
     net-http (0.6.0)
       uri
-    net-imap (0.5.6)
+    net-imap (0.5.7)
       date
       net-protocol
     net-pop (0.1.2)