added test and ci

.gitlab-ci.yml

+image: node:6
+
+before_script:
+  - npm install
+  
+test:
+  script:
+    - npm test
\ No newline at end of file

dao/sum.js

+function sum(a, b) {
+  return a + b;
+}
+module.exports = sum;
\ No newline at end of file

dao/sum.test.js

+const sum = require('./sum');
+
+
+/*
+beforeEach(() => {
+  initializeCityDatabase();
+});
+
+afterEach(() => {
+  clearCityDatabase();
+});
+
+test('city database has Vienna', () => {
+  expect(isCity('Vienna')).toBeTruthy();
+});
+
+test('city database has San Juan', () => {
+  expect(isCity('San Juan')).toBeTruthy();
+}); */
+
+test("adds 1 + 2 to equal 3", () => {
+  expect(sum(1, 2)).toBe(3);
+});
\ No newline at end of file

package.json

+{
+	"name": "myPackage",
+	"jest": {
+        "verbose": true,
+		"collectCoverage": true,
+        "coverageReporters": ["json", "html"]
+    },
+	"version": "0.0.1",
+	"dependencies": {
+		"body-parser": "^1.18.3",
+		"express": "^4.16.3",
+		"jest": "^23.6.0",
+		"mysql": "^2.16.0"
+	},
+	"scripts": {
+		"test": "jest"
+	}
+}