Added e2e tests and snapshot files

e2e/spec/gitGraph.spec.js

@@ -0,0 +1,29 @@
+/* eslint-env jest */
+import { imgSnapshotTest } from '../helpers/util.js'
+const { toMatchImageSnapshot } = require('jest-image-snapshot')
+
+expect.extend({ toMatchImageSnapshot })
+
+describe('Sequencediagram', () => {
+  it('should render a simple git graph', async () => {
+    await imgSnapshotTest(page, `
+    gitGraph:
+      options
+      {
+          "nodeSpacing": 150,
+          "nodeRadius": 10
+      }
+      end
+      commit
+      branch newbranch
+      checkout newbranch
+      commit
+      commit
+      checkout master
+      commit
+      commit
+      merge newbranch
+      `,
+    {})
+  })
+})