Bump imagemin-webpack-plugin from 1.6.1 to 2.4.2

Bumps [imagemin-webpack-plugin](https://github.com/Klathmon/imagemin-webpack-plugin) from 1.6.1 to 2.4.2.
- [Release notes](https://github.com/Klathmon/imagemin-webpack-plugin/releases)
- [Commits](https://github.com/Klathmon/imagemin-webpack-plugin/compare/v1.6.1...v2.4.2)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

package.json

@@ -32,7 +32,7 @@
     "eslint-plugin-import": "2.22.1",
     "extract-text-webpack-plugin": "^3.0.1",
     "html-webpack-plugin": "^2.30.1",
-    "imagemin-webpack-plugin": "^1.6.1",
+    "imagemin-webpack-plugin": "^2.4.2",
     "node-sass": "^4.13.0",
     "postcss-cssnext": "^3.0.2",
     "postcss-loader": "^2.0.8",