Add sample unit test

test/unit/specs/FormWizard.spec.js

@@ -0,0 +1,28 @@
+import Vue from 'vue'
+import VueFormWizard from './../../../src/components/FormWizard.vue'
+import TabContent from './../../../src/components/TabContent.vue'
+
+function init () {
+  Vue.component('form-wizard', VueFormWizard)
+  Vue.component('tab-content', TabContent)
+}
+
+describe('FormWizard.vue', () => {
+  beforeEach(() => {
+    init()
+  })
+  it('should render correct contents', (done) => {
+    const vm = new Vue({
+      template: `<form-wizard ref="wizard">
+                   <tab-content>First</tab-content> 
+                   <tab-content>Second</tab-content> 
+                </form-wizard>`
+    }).$mount()
+
+    let wizard = vm.$children[0]
+    let wizardComp = vm.$refs.wizard
+    expect(wizard.$children.length).to.equal(2)
+    expect(wizardComp.activeTabIndex).to.equal(0)
+    done()
+  })
+})