Add Kilometers/Hour to Miles/Hour conversion and reverse

test/mphToKph/mphToKph.test.js

@@ -0,0 +1,12 @@
+const expect = require('expect');
+const mphToKph = require('./mphToKph.js');
+
+test('mphToKph is a Function', () => {
+  expect(mphToKph).toBeInstanceOf(Function);
+});
+test('Returns kph from mph.', () => {
+  expect(mphToKph(10)).toBe(16.09344000614692);
+});
+test('Returns kph from mph.', () => {
+  expect(mphToKph(85.9)).toBe(138.24264965280207);
+});