* update boilerplate header and apply go fmt

Signed-off-by: Carlos Panato <ctadeu@gmail.com>

* lints: fix golangci-lint issues

Signed-off-by: Carlos Panato <ctadeu@gmail.com>

* updated based on feedback

Signed-off-by: Carlos Panato <ctadeu@gmail.com>

This is the first step in code reorganization. This follows the patterns
from kubernetes/kubernetes - each binary gets a directory under cmd/.
The main.go file for each binary lives there.
The commands live under cmd//app.