Clojure Tooling Improvements

[martinklepsch]

Just creating a list of things that might be worth doing or at least considering:

• Integrate cljs-devtools
• Switch to shadow-cljs — Figwheel is nice but as far as I can see shadow-cljs improves several aspects, particularly around caching.
• Figure out to what degree we might want to use the new clj tool
• Integrate re-frame-10x — We already have re-frisk but for web apps (in contrast to ReactNative) re-frame-10x might be better?

If you'd like to work on any of these we can create a bounty for that, just let us know on Riot.