Missing ldflags parameter

At this moment, godog doesn't support ldflags feature like go build or run commands.

If the application needs to use an external library already compiled, that need to be linked to the application, it's not possible.

The usage of the ldflags flag throws this error:
```flag provided but not defined: -ldflags```

Start by locating godog's command-line flag parsing and the code that invokes Go build or run commands. Reproduce the reported “flag provided but not defined: -ldflags” error, then verify that an ldflags value can be accepted and passed through when the application requires it.

Written by the indexing model from the issue text.