Added test of usage via webpack to the e2e tests

e2e/spec/webpackUsage.spec.js

@@ -0,0 +1,16 @@
+/* eslint-env jest */
+const { toMatchImageSnapshot } = require('jest-image-snapshot')
+
+expect.extend({ toMatchImageSnapshot })
+
+describe('Sequencediagram', () => {
+  it('should render a simple sequence diagrams', async () => {
+    const url = 'http://localhost:9000/webpackUsage.html'
+
+    await page.goto(url)
+
+    const image = await page.screenshot()
+
+    expect(image).toMatchImageSnapshot()
+  })
+})