Plugin stopped working with Webpack 4

[dvbobrov]

Type:

• bug
• feature
• enhancement
• question

Environment:

• OS: Mac OS
• Library Version: 0.8.2

I'm going to open a PR:

• yes
• no

Description:
When plugin is used with Webpack 4, it crashes with the following exception:

TypeError: this._compiler.hooks.afterEmit is not a function
    at CompilerEventsFacade.afterEmit (/redacted/node_modules/webpack-chrome-extension-reloader/dist/webpack:/src/utils/CompilerEventsFacade.ts:31:39)
    at ChromeExtensionReloader.apply (/redacted/node_modules/webpack-chrome-extension-reloader/dist/webpack:/src/ChromeExtensionReloader.ts:45:31)
    at webpack (/redacted/node_modules/webpack/lib/webpack.js:37:12)
    at processOptions (/redacted/node_modules/webpack-cli/bin/webpack.js:437:16)
    at yargs.parse (/redacted/node_modules/webpack-cli/bin/webpack.js:513:3)
    at Object.parse (/redacted/node_modules/webpack-cli/node_modules/yargs/yargs.js:552:18)
    at /redacted/node_modules/webpack-cli/bin/webpack.js:218:8
    at Object.<anonymous> (/redacted/node_modules/webpack-cli/bin/webpack.js:515:3)
    at Module._compile (internal/modules/cjs/loader.js:702:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:713:10)
    at Module.load (internal/modules/cjs/loader.js:612:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:551:12)
    at Function.Module._load (internal/modules/cjs/loader.js:543:3)
    at Module.require (internal/modules/cjs/loader.js:650:17)
    at require (internal/modules/cjs/helpers.js:20:18)
    at Object.<anonymous> (/redacted/node_modules/webpack/bin/webpack.js:157:2)
    at Module._compile (internal/modules/cjs/loader.js:702:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:713:10)
    at Module.load (internal/modules/cjs/loader.js:612:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:551:12)
    at Function.Module._load (internal/modules/cjs/loader.js:543:3)
    at Function.Module.runMain (internal/modules/cjs/loader.js:744:10)
    at startup (internal/bootstrap/node.js:238:19)
    at bootstrapNodeJSCore (internal/bootstrap/node.js:572:3)