DeprecationWarning: Tapable.plugin is deprecated. Webpack 4

[WaqasIbrahim]

Hi, When using Webpack 4 I receive the following warning message:

DeprecationWarning: Tapable.plugin is deprecated. Use new API on `.hooks` instead
    at WebpackObfuscator.apply (../../node_modules/webpack-obfuscator/index.js:16:18)

The warning can be fixed by using the new hooks API and replacing

compiler.plugin('compilation', function (compilation) {
    compilation.plugin("optimize-chunk-assets", function (chunks, callback) {

With this:

compiler.hooks.compilation.tap('WebpackObfuscator', function (compilation) {
    compilation.hooks.optimizeChunkAssets.tap('WebpackObfuscator', function (chunks) {

And removing the callback call. You can also keep backwards compatibility. Please take a look at my commit here.

[0x657373656C6C]

@WaqasIbrahim Would you be so kind as to submit a PR so that this can be merged?

[WaqasIbrahim]

@yourapiexpert, I upgraded major versions of packages in that commit so I am not sure If the author would want that.