Migrate to Webpack 3 and Yarn

npm@5.4.0 completely broke SauceLabs integration, which made me lock it at 5.3.0 for now. Also Grunt’s config is slightly growing too much and getting mixed with npm scripts. This duo is working for now, but it’d be nice to get them updated soon.

Same goes for raven-node.

[austinpray]

I’m getting sort of discouraged.

1. Right off the bat the webpack output is 10kb heavier than the grunt output
2. webpack is not ie8 compatible, so we have to shim the es5 methods it uses in the module loading boilerplate. This adds another 20kb to the bundle.

I know you guys are trying to keep the output small as possible, so this sorta seems like a dealbreaker to me.

[kamilogorek]

@saiichihashimoto we are <10kb gzipped. Changing build system won’t reduce that much, as we don’t have any external dependencies.