feat(restish): properly handle binary download and use
What
This MR fix the way we handle external binaries such as Restish. It also fix some minor coding style issue.
Why
Because we hardcoded the link to the linux-x86_64 version of restish binary, so it did not work on Mac / Windows computers.
How
Use the platform
module to have the correct URL, and throw a proper error when the url is wrong.
References
Closes #9 (closed)