Linting applied and updated Kotlin and Gradle

$ flutter --version
Flutter 3.0.0 • channel unknown • unknown source
Framework • revision ee4e09cce0 (3 months ago) • 2022-05-09 16:45:18 -0700
Engine • revision d1b9a6938a
Tools • Dart 2.17.0 • DevTools 2.12.2

Addresses #6