Bump cross-env from 6.0.3 to 7.0.3 (#93)

Bumps [cross-env](https://github.com/kentcdodds/cross-env) from 6.0.3 to 7.0.3.
- [Release notes](https://github.com/kentcdodds/cross-env/releases)
- [Changelog](https://github.com/kentcdodds/cross-env/blob/master/CHANGELOG.md)
- [Commits](kentcdodds/cross-env@v6.0.3...v7.0.3)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Author: dependabot-preview[bot]

package.json

@@ -50,7 +50,7 @@
     "@types/react": "^16.8.19",
     "@types/react-dom": "^16.8.4",
     "@types/warning": "^3.0.0",
-    "cross-env": "^6.0.0",
+    "cross-env": "^7.0.3",
     "enzyme": "^3.3.0",
     "enzyme-adapter-react-16": "^1.14.0",
     "enzyme-to-json": "^3.4.0",