Upgrades react-scripts to ^1.1.5 (facebookarchive#2042)

Summary:
**Summary**

Upgrades react-scripts to ^1.1.5 to remove an indirect dependency on the [vulnerable package macaddress@0.2.8](https://snyk.io/vuln/SNYK-JS-MACADDRESS-12141).

**Test Plan**

Smoke test the Draft.js playground

```
cd examples/draft-0-10-0/playground
yarn install
yarn run start
```
Pull Request resolved: facebookarchive#2042

Reviewed By: anarelion

Differential Revision: D14560176

Pulled By: anarelion

fbshipit-source-id: b109049e545361db9ed0a35b7242fac5fd85cdc3

examples/draft-0-10-0/playground/package.json

@@ -5,14 +5,14 @@
   "dependencies": {
     "codemirror": "^5.32.0",
     "draft-convert": "^2.0.1",
-    "draft-js": "file:../../../",
+    "draft-js": "file:../../..",
     "immutable": "^3.8.2",
     "react": "^16.2.0",
     "react-codemirror2": "^3.0.7",
     "react-dom": "^16.2.0",
     "react-json-tree": "^0.11.0",
     "react-panelgroup": "^1.0.5",
-    "react-scripts": "1.0.17"
+    "react-scripts": "^1.1.5"
   },
   "scripts": {
     "start": "react-scripts start",