chore: assertion check for webpack version (#584)

Author: 1999

src/instance.ts

@@ -137,6 +137,12 @@ export function ensureInstance(
 )
 let compiler = <any>webpack._compiler
 
+if (!rootCompiler.hooks) {
+throw new Error('It looks like you\'re using an old webpack version without hooks support. ' +
+'If you\'re using awesome-script-loader with React storybooks consider ' +
+'upgrading @storybook/react to at least version 4.0.0-alpha.3');
+}
+
 setupWatchRun(compiler, instanceName)
 setupAfterCompile(compiler, instanceName)