Bump axios from 0.19.0 to 0.21.1 in /react-shopping-cart-demo

Bumps [axios](https://github.com/axios/axios) from 0.19.0 to 0.21.1.
- [Release notes](https://github.com/axios/axios/releases)
- [Changelog](https://github.com/axios/axios/blob/v0.21.1/CHANGELOG.md)
- [Commits](axios/axios@v0.19.0...v0.21.1)

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

Author: dependabot[bot]