Make ffmpeg executable path configurable

[kodie]

It seems like this package is abandoned but it still works better for me than the alternative for the project I'm currently working on. One thing I needed to be able to do is change the ffmpeg executable path so that it can work with ffmpeg-static, it seems like some effort was made to make this configurable (c099e37) however it was still hard-coded for the video object. So I went a different route.

The bin is now a setting that can be configured like this:

const pathToFfmpeg = require('ffmpeg-static')
const ffmpeg = require('ffmpeg')

const video = await new ffmpeg(filePath, { bin: pathToFfmpeg })

I cut my branch from the 46e8bb5 commit as that is the latest version that is published to NPM (I also couldn't get what's currently on the repo to work).

Even though this package is abandoned I figured I'd still put up the PR just in case anyone else runs into this issue.

You can use my version of this package which is the current version on NPM with the added configurable bin by placing this under the dependencies in your package.json file:

"ffmpeg": "git@github.com:kodie/node-ffmpeg.git#kodie/fix-bin-path"