Use figwheel to make an nREPL server available in ClojureScript during development

[WilliamParker]

There was some discussion of setting up the project.clj so that we could create an nREPL server for ClojureScript during development. See #285 (comment) and #285 (comment)

This didn't really seem like part of issue 285 so I decided to create a new issue to track on it. I agree that this would be a good thing to have.

cc @alex-dixon @mrrodriguez

[alex-dixon]

I can implement if it's desired. For those who use IntelliJ it's dangerously close to having the same REPL setup for CLJS as CLJ.

I think the changes would include:

• Adddev folder to the project root with a user.clj file that can be loaded into a lein repl or autoloaded by adding :repl-options {:init-ns user} under dev profile in project.clj.
• Add dev to :source-paths
• Add the following :figwheel options to the top level of project.clj:

:figwheel
  {:http-server-root "public"
   :nrepl-port 7002
   :nrepl-middleware [cemerick.piggieback/wrap-cljs-repl]}

• Add figwheel-sidecar to dev dependencies (should use same version as lein-figwheel)
• Add com.cemerick/piggieback to dev dependencies

[WilliamParker]

Sounds good to me @alex-dixon that would be helpful, thanks. Regarding adding a namespace in /dev to the :source-paths - we'd probably want to avoid that namespace being added into the deployed clara-rules jar though.