Cleanup Jest config (#6654)

General cleanup after the [Jest 24 PR](#6278). 

This also includes `jsdom@14` via https://www.npmjs.com/package/jest-environment-jsdom-fourteen. Since we have a node >= 8.10 requirement, we are able to use the latest version of `jsdom` which includes additional implementations of browser APIs such as `MutationObserver` (which we had an issue filed for over at #6617).

/cc @SimenB. Is there more you recommend we do to cleanup our [Jest config](b0cbf2caa1/packages/react-scripts/scripts/utils/createJestConfig.js) for TypeScript?

Co-authored-by: Ian Sutherland <ian@iansutherland.ca>

packages/react-error-overlay/package.json

@@ -33,9 +33,8 @@
     "@babel/code-frame": "7.0.0",
     "@babel/core": "7.3.4",
     "anser": "1.4.8",
-    "babel-core": "7.0.0-bridge.0",
     "babel-eslint": "10.0.1",
-    "babel-jest": "24.5.0",
+    "babel-jest": "24.7.1",
     "babel-loader": "8.0.5",
     "babel-preset-react-app": "^7.0.2",
     "chalk": "^2.4.2",
@@ -49,7 +48,7 @@
     "eslint-plugin-react": "7.12.4",
     "flow-bin": "^0.63.1",
     "html-entities": "1.2.1",
-    "jest": "24.5.0",
+    "jest": "24.7.1",
     "jest-fetch-mock": "2.1.1",
     "object-assign": "4.1.1",
     "promise": "8.0.2",