Cleanup - goimports
README.md - Cleanup
Rename command line utility file

Go generates the binary based on the package name, not
the file. So the `askduck.go` nomenclature didn't add any value,
as the binary would remain as `goduckgo`.

As seen in the Go community, `main.go` fits better
the language convention.
Merge pull request #1 from fern4lvarez/renewal

Renewal