added error test

Author: mtrezza

spec/Errors.spec.js

@@ -0,0 +1,12 @@
+'use strict';
+
+const Errors = require('../src/Errors');
+
+describe('Errors', () => {
+  it('should create a custom error', () => {
+    const message = "Example Error";
+    const error = Errors.customError(message);
+    expect(error.message).toBe(message);
+    expect(error instanceof Error).toBeTrue();
+  });
+});