Update all Babel package versions.

Author: lindapaiste

karma.conf.js

@@ -24,7 +24,7 @@ module.exports = config => {
       // use different import syntaxes so it's not easy to just require it here.
       // Maybe this could be put into a JSON file, but the include in the module
       // rules is dynamic.
-      entry: ["babel-polyfill", "./src/index.js"],
+      entry: ["@babel/polyfill", "./src/index.js"],
       output: {
         libraryTarget: "umd",
         filename: "ml5.js",