Possibility to run only specific scenario

[bkielbasa]

Is your feature request related to a problem? Please describe.
Sometimes it's useful to run only 1 scenario. Adding tag and running with only this tag helps but IMO it would be a clearer way.

Describe the solution you'd like
Maybe we can add a new parameter which will accept the scenario(s) name to run:

go test ./... --only-scenario="scanario name goes here"

Describe alternatives you've considered
Adding tags is a cool alternative and works but the problem is that we have to spam our features with tags which are not related to the domain at all.