fix: upgrade @aws-amplify/cache from 3.1.19 to 3.1.20 (#112)

Snyk has created this PR to upgrade @aws-amplify/cache from 3.1.19 to 3.1.20.

See this package in npm:
https://www.npmjs.com/package/@aws-amplify/cache

See this project in Snyk:
https://app.snyk.io/org/johanneskonings/project/b30410ce-f052-409e-904e-a2e4798c61db?utm_source=github&utm_medium=upgrade-pr

Co-authored-by: Johannes Konings <johannes.konings@outlook.com>