Migrated tests to jest

Used jest-codemods to migrate, will have to pass everything by hand before we can merge.

test/runAsync/runAsync.js

@@ -1,16 +0,0 @@
-const runAsync = fn => {
-const worker = new Worker(
-URL.createObjectURL(new Blob([`postMessage((${fn})());`]), {
-type: 'application/javascript; charset=utf-8'
-})
-);
-return new Promise((res, rej) => {
-worker.onmessage = ({ data }) => {
-res(data), worker.terminate();
-};
-worker.onerror = err => {
-rej(err), worker.terminate();
-};
-});
-};
-module.exports = runAsync;