justforfunc #29: dependency injection in a code review HD

Dependency Injection (aka Inversion of Control) is a great technique to write code that is easier to reuse and test. In this episode we review https://github.com/gerlacdt/db-key-value-store and as a result create a pretty large PR: https://github.com/gerlacdt/db-key-value-store/pull/1 References: - PR: https://github.com/gerlacdt/db-key-value-store/pull/1 - Dependency Injection: https://en.wikipedia.org/wiki/Dependency_injection - filebuffer: https://github.com/mattetti/filebuffer - proposal on bytes.Buffer.Seek: https://github.com/golang/go/issues/21899