Add @types/events so that clean installs run successfully

Author: spautz

package.json

@@ -43,6 +43,7 @@
     "@storybook/addon-storysource": "^5.1.11",
     "@storybook/addons": "^5.1.11",
     "@storybook/react": "^5.1.11",
+    "@types/events": "^3.0.0",
     "@types/react": "^16.9.2",
     "@types/react-dom": "^16.9.0",
     "babel-loader": "^8.0.6",