Create tags for the Go reference

[kaklakariada]

The Go reference (https://pkg.go.dev/github.com/exasol/exasol-driver-go) does not list any tags. This means that users must use snapshot tags like v0.0.0-20211014072629-7d551578a654.

It might be enough to use version tags with a v prefix, e.g. v0.2.1.

Also add a badge to the Readme: https://pkg.go.dev/badge/

[![Go Reference](https://pkg.go.dev/badge/github.com/exasol/exasol-driver-go.svg)](https://pkg.go.dev/github.com/exasol/exasol-driver-go)

[Nightapes]

Yes, the v is needed:
Works with the newest tag github.com/exasol/exasol-driver-go v0.1.2

[kaklakariada]

Implemented with #43