add 2 tests, flattenDepth & formatDuration

update CamelCase test cases

test/flattenDepth/flattenDepth.test.js

@@ -5,6 +5,7 @@ test('Testing flattenDepth', (t) => {
 	//For more information on all the methods supported by tape
 	//Please go to https://github.com/substack/tape
 	t.true(typeof flattenDepth === 'function', 'flattenDepth is a Function');
+	t.deepEqual(flattenDepth([1, [2], 3, 4]), [1, 2, 3, 4], "Flattens an array up to the specified depth");
 	//t.deepEqual(flattenDepth(args..), 'Expected');
 	//t.equal(flattenDepth(args..), 'Expected');
 	//t.false(flattenDepth(args..), 'Expected');