Version 1.6.2-1 of ring-clojure is marked for autoremoval from testing on Sun 10 Mar 2019. It is affected by #918437. The removal of ring-clojure will also cause the removal of (transitive) reverse dependencies: bidi-clojure, comidi-clojure, compojure-clojure, metrics-clojure, puppetdb, puppetlabs-ring-middleware-clojure, ring-defaults-clojure, ring-headers-clojure, ring-ssl-clojure, trapperkeeper-metrics-clojure, trapperkeeper-status-clojure, trapperkeeper-webserver-jetty9-clojure. It depends (transitively) on clj-time-clojure, affected by #917743.
You should try to prevent the removal by fixing these RC bugs.