Add webpack3 to benchmark

[TheLarkInn]

Should find a way to be able to run webpack 3 also. Maybe there is a way to leverage yarn aliases.

[adhrinae]

You can install another version of webpack like this.

yarn add webpack3@npm:webpack

since this process changes the symbolic link of ./node_modules/.bin/webpack, I tried to change it directly. and made another symbolic link like this.

lrwxr-xr-x  1 rinae  staff    25B Dec 21 14:03 webpack -> ../webpack/bin/webpack.js
lrwxr-xr-x  1 rinae  staff    29B Dec 21 14:02 webpack-cli -> ../webpack-cli/bin/webpack.js
lrwxr-xr-x  1 rinae  staff    26B Dec 21 14:02 webpack3 -> ../webpack3/bin/webpack.js

The problem is that webpack-cli always refer to webpack which is version 4.0.0-alpha1. so I couldn't bundle it using webpack3.

Perhaps you should create a monorepo for different kinds of benchmark.