Add reverse binary exercise

Based on [Spotify Puzzles exercise](http://labs.spotify.com/puzzles/)
Nope, that's the only reason. Gives my eyes less work to do. I definitely
don't like mixing styles (though that doesn't apply here).
On Jul 12, 2014 11:34 AM, "Robert Boyd" <notifications@github.com> wrote:

> In src-answers/clojure_katas/reverse_binary.clj:
>
> > +
> > +(defn decimal->binary
> > +  [^Integer x]
> > +  (Integer/toString x 2))
> > +
> > +(defn binary->decimal
> > +  [^String x]
> > +  (Integer/parseInt x 2))
> > +
> > +(defn str-reverse
> > +  [^String s]
> > +  (apply str (reverse s)))
> > +
> > +(defn reverse-binary
> > +  [^Integer x]
> > +  (binary->decimal(str-reverse(decimal->binary x))))
>
> @gfredericks <https://github.com/gfredericks> do you prefer parens around
> unary functions inside thread-first just for consistency with n-ary
> functions? in https://github.com/bbatsov/clojure-style-guide I notice he
> doesn't include them, and I never do, so I'm curious if I'm missing another
> advantage.
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/marshallshen/clojure-katas/pull/3/files#r14854028>.
>