Update ring dependency
Update ring dependency

Ring < 1.5.1 has a path-walking vulnerability when used from the
filesystem (not in an uberjar or war). See
https://groups.google.com/d/msg/clojure-sec/WOMCpKAFkDE/ObzkAYhnBgAJ

immutant/immutant,immutant/immutant,immutant/immutant,immutant/immutant