Test migration to jest by hand

Apparently using regular expressions is way easier.

test/factorial/factorial.test.js

@@ -0,0 +1,13 @@
+const expect = require('expect');
+const factorial = require('./factorial.js');
+
+
+  test('factorial is a Function', () => {
+  expect(factorial).toBeInstanceOf(Function);
+});
+  t.equal(factorial(6), 720, "Calculates the factorial of 720");
+  t.equal(factorial(0), 1, "Calculates the factorial of 0");
+  t.equal(factorial(1), 1, "Calculates the factorial of 1");
+  t.equal(factorial(4), 24, "Calculates the factorial of 4");
+  t.equal(factorial(10), 3628800, "Calculates the factorial of 10");
+