@jabanses: Proto REPL has a default leiningen project set to Clojure 1.8. To use a different version you should create a new leiningen project with 1.9 and use that. You can try cloning the Proto REPL demo and upgrading it to 1.9. Fair warning that I haven't tried that yet so there may be some problems with it.
@fingertoe: I don't think the warning is related. There's a separate location to see styles in the developer console. I'll get a screenshot later to show you what I mean.