Test migration to jest by hand

Apparently using regular expressions is way easier.

test/pipeAsyncFunctions/pipeAsyncFunctions.js

@@ -0,0 +1,2 @@
+const pipeAsyncFunctions = (...fns) => arg => fns.reduce((p, f) => p.then(f), Promise.resolve(arg));
+module.exports = pipeAsyncFunctions;