Added new algoritm (#433)

String/CheckVowels.test.js

@@ -0,0 +1,12 @@
+import { checkVowels } from './CheckVowels'
+
+describe('Test the checkVowels function', () => {
+  it('expect throws on use wrong param', () => {
+    expect(() => checkVowels(0)).toThrow()
+  })
+  it('count the vowels in a string', () => {
+    const value = 'Mad World'
+    const countVowels = checkVowels(value)
+    expect(countVowels).toBe(2)
+  })
+})