Test migration to jest by hand

Apparently using regular expressions is way easier.

test/renameKeys/renameKeys.js

@@ -0,0 +1,9 @@
+const renameKeys = (keysMap, obj) =>
+Object.keys(obj).reduce(
+(acc, key) => ({
+...acc,
+...{ [keysMap[key] || key]: obj[key] }
+}),
+{}
+);
+module.exports = renameKeys;