Add Hawk dependency and auto reloading

[kwrooijen]

Problem

There is no way to auto reload your Duct project currently. See: https://github.com/duct-framework/core/issues/12

Solution

As stated in https://github.com/duct-framework/core/issues/12 we can add Hawk as a dependency and write our own watcher.

Usage:

lein repl
(dev)
(auto-reset)
;; From here you can change any (Clojure / EDN) file 
;; in `src/` or `resources/` and the `(reset)` command 
;; will execute in a separate thread.

Notes

• The auto-reset-handler was throwing an illegal state exception because of *ns*

  ;; java.lang.IllegalStateException: Can't change/establish root binding of: *ns* with set

  I fixed this by binding ns and then changing the namespace to dev. However I'd gladly accept a better solution

• There's quite a lot of additions to dev.clj, and most of it is private. Would you like me to create a separate namespace for the auto reloading code? If so would you please provide a suggestion?

[weavejester]

Thanks for the PR. Before we talk about the actual code, the code needs to be moved to the duct.core.repl namespace, which is part of the duct/core library. This avoids unnecessary code in the project template.

[kwrooijen]

Thanks for your feedback. I'll close this and move it to core.

[kwrooijen]

Moved to https://github.com/duct-framework/core/pull/24