Migrated tests to jest

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

test5/pipeFunctions/pipeFunctions.js

@@ -0,0 +1,2 @@
+const pipeFunctions = (...fns) => fns.reduce((f, g) => (...args) => g(f(...args)));
+module.exports = pipeFunctions;