Add Windows support

As discussed in an email with [Jonathan](https://github.com/jpowers1981), codeclimate-test-report fails on Windows, since the payloads are broken. The server does not report this, however, which is further confusing.

The problems involve single-quotes not being a valid quoting mechanism on Windows (and since they aren't needed in this case, they were removed), and paths on Windows being delimited by `\` instead of `/`, which broke in CodeClimate back-end.

This set of changes should add Windows support to javascript-test-reported, which I guess is probably what was actually intended (to have Windows support), but the lack of error response from CodeClimate's back-end made this go under the radar.

Hope this helps! :+1: