Remove @babel/polyfill, add regenerator-runtime

Author: catarak

client/jest.setup.js

@@ -1,4 +1,4 @@
-import '@babel/polyfill';
+import 'regenerator-runtime/runtime';
 
 // See: https://github.com/testing-library/jest-dom
 // eslint-disable-next-line import/no-extraneous-dependencies

index.js

@@ -7,7 +7,7 @@ if (process.env.NODE_ENV === 'production') {
   require('@babel/register')({
     presets: ["@babel/preset-env"]
   });
-  require('@babel/polyfill');
+  require('regenerator-runtime/runtime');
   //// in development, let .env values override those in the environment already (i.e. in docker-compose.yml)
   // so commenting this out makes the docker container work.
   // if (process.env.NODE_ENV === 'development') {