[Feature] Log Level and noisy puppeteer logs

[aw-davidson]

I'm looking to implement improved logging for backstop Backstop. My main issue with backstop logging is the logs coming from "Browser Console Log". Maybe there should just be a config option to turn these off or on, like a verbose flag.

There other option is to implement logging levels which may be too heavy of a solution. I've read up on the discussion over #822 and have some questions. 1. When a level is set, should logging only occur at that level or should logging occur at that level and also at other levels "below" it 2. Should all logs use the special logger in logger.js? 3. what would logLevel: 'OFF' do - would it turn logging output off or would it log outputs at all levels?

How should we deal with the main issue of noisy browser console logs

[pixelastic]

FWIW, I disabled browser console logs by setting console.log = () => {}; in the onBefore script. This simply override the default console.log with a noop function