fix(starters): update react monorepo to ^16.8.2 (#11781)

This PR contains the following updates:

| Package | Type | Update | Change | References |
|---|---|---|---|---|
| react | dependencies | patch | `^16.8.1` -> `^16.8.2` | [homepage](https://reactjs.org/), [source](https://github.com/facebook/react) |
| react-dom | dependencies | patch | `^16.8.1` -> `^16.8.2` | [homepage](https://reactjs.org/), [source](https://github.com/facebook/react) |

---

### Release Notes

<details>
<summary>facebook/react</summary>

### [`v16.8.2`](https://github.com/facebook/react/blob/master/CHANGELOG.md#&#8203;1682-February-14-2019)

[Compare Source](https://github.com/facebook/react/compare/v16.8.1...v16.8.2)

##### React DOM

-   Fix `ReactDOM.render` being ignored inside `useEffect`. ([@&#8203;gaearon](https://github.com/gaearon) in [#&#8203;14799](https://github.com/facebook/react/pull/14799))
-   Fix a crash when unmounting empty portals. ([@&#8203;gaearon](https://github.com/gaearon) in [#&#8203;14820](https://github.com/facebook/react/pull/14820))
-   Fix `useImperativeHandle` to work correctly when no deps are specified. ([@&#8203;gaearon](https://github.com/gaearon) in [#&#8203;14801](https://github.com/facebook/react/pull/14801))
-   Fix `crossOrigin` attribute to work in SVG `image` elements. ([@&#8203;aweary](https://github.com/aweary) in [#&#8203;14832](https://github.com/facebook/react/pull/14832))
-   Fix a false positive warning when using Suspense with Hooks. ([@&#8203;gaearon](https://github.com/gaearon) in [#&#8203;14821](https://github.com/facebook/react/pull/14821))

##### React Test Utils and React Test Renderer

-   Include component stack into the `act()` warning. ([@&#8203;threepointone](https://github.com/threepointone) in [#&#8203;14855](https://github.com/facebook/react/pull/14855))

</details>

---

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starters/blog/package.json

@@ -26,8 +26,8 @@
     "gatsby-transformer-remark": "^2.2.5",
     "gatsby-transformer-sharp": "^2.1.13",
     "prismjs": "^1.15.0",
-    "react": "^16.8.1",
-    "react-dom": "^16.8.1",
+    "react": "^16.8.2",
+    "react-dom": "^16.8.2",
     "react-helmet": "^5.2.0",
     "react-typography": "^0.16.18",
     "typeface-merriweather": "0.0.54",

starters/default/package.json

@@ -14,8 +14,8 @@
     "gatsby-source-filesystem": "^2.0.20",
     "gatsby-transformer-sharp": "^2.1.13",
     "prop-types": "^15.7.2",
-    "react": "^16.8.1",
-    "react-dom": "^16.8.1",
+    "react": "^16.8.2",
+    "react-dom": "^16.8.2",
     "react-helmet": "^5.2.0"
   },
   "keywords": [

starters/hello-world/package.json

@@ -13,8 +13,8 @@
   },
   "dependencies": {
     "gatsby": "^2.1.2",
-    "react": "^16.8.1",
-    "react-dom": "^16.8.1"
+    "react": "^16.8.2",
+    "react-dom": "^16.8.2"
   },
   "repository": {
     "type": "git",