Allow updates to html to be shown  when reloading the page in the browser

I've substituted the enlive machinery to inject the repl-js script with hickery to allow live refreshing of the html code. With enlive, as templates are compiled into functions, if one modifies index.html, the ring.server namespace must be reloaded.

I've also upgraded austin to 0.1.4 because, I don't know why, with the 0.1.3 version I get sometimes a broken pipe exception.