Add 32bit support. Now all sc binaries are accounted for

Solves Issue#27.

Ran around trying to figure out why saucelabs wasn't playing nice on a linux box I was working with.
Turned out to be an architectural problem, I was on a 32bit system.

So I added the 32bit linux binary, current version: 4.3.5 (32bit)
And a special case in index.js to account for this.

Now all binaries compiled by sauce labs are accounted for :)