Add flattenObject, unflattenObject

Tagged and tested. Quite complex methods btw.

test/flattenObject/flattenObject.js

@@ -0,0 +1,12 @@
+const flattenObject = (obj, prefix = '') =>
+Object.keys(obj).reduce((acc, k) => {
+const pre = prefix.length ? (prefix + '.') : '';
+if (typeof obj[k] === 'object')
+Object.assign(
+acc,
+flattenObject(obj[k], pre + k)
+);
+else acc[pre + k] = obj[k];
+return acc;
+}, {});
+module.exports = flattenObject;