Updated the test system

test/radsToDegrees.test.js

@@ -0,0 +1,9 @@
+const expect = require('expect');
+const {radsToDegrees} = require('./_30s.js');
+
+test('radsToDegrees is a Function', () => {
+  expect(radsToDegrees).toBeInstanceOf(Function);
+});
+test('Returns the appropriate value', () => {
+  expect(radsToDegrees(Math.PI / 2)).toBe(90);
+});