pkg/generator: add stub/handler.go generator

[fanminshi]

No description provided.

[fanminshi]

manual test:

func TestGenHandler(t *testing.T) {
	buf := &bytes.Buffer{}
	if err := renderHandler(buf); err != nil {
		t.Error(err)
		return
	}
	if err := ioutil.WriteFile("./handler.go", buf.Bytes(), 0644); err != nil {
		t.Error(err)
	}
}

Output:

package stub

import (
	"github.com/coreos/operator-sdk/pkg/sdk/types"
)

type Handler struct {
	// Fill me
}

func (h *Handler) Handle(ctx types.Context, event types.Event) {
	// Fill me
}

[fanminshi]

cc/ @hongchaodeng @hasbro17

[hongchaodeng]

No need for this example. Developers can look into the template directly.

[fanminshi]

sure will remove.

[fanminshi]

done!

[hongchaodeng]

LGTM after nit