add first test with jest

packages/tiptap/src/utils/Editor.js

@@ -26,6 +26,7 @@ export default class Editor {
   setOptions(options) {
     const defaultOptions = {
       editable: true,
+      extensions: [],
       content: '',
       onUpdate: () => {},
     }

packages/tiptap/src/utils/Editor.spec.js

@@ -0,0 +1,7 @@
+import Editor from './Editor'
+
+test('can create editor', () => {
+  const editor = new Editor()
+
+  expect(editor).toBeDefined()
+})