feat: upgrade assets-webpack-plugin to 5.1.2

closes #473

Author: jlengrand

package.json

@@ -22,7 +22,7 @@
     "@babel/plugin-transform-runtime": "7.11.5",
     "@babel/preset-env": "7.11.5",
     "@babel/runtime": "7.11.2",
-    "assets-webpack-plugin": "3.9.12",
+    "assets-webpack-plugin": "5.1.2",
     "autoprefixer": "10.0.1",
     "babel-loader": "8.1.0",
     "babel-runtime": "6.26.0",