Publish helper structs and methods.

Signed-off-by: David Calavera <david.calavera@gmail.com>

wincred/cmd/main_windows.go

@@ -6,5 +6,5 @@ import (
 )
 
 func main() {
-	credentials.Serve(wincred.New())
+	credentials.Serve(wincred.Wincred{})
 }

wincred/wincred_windows.go

@@ -5,15 +5,11 @@ import (
 	"github.com/docker/docker-credential-helpers/credentials"
 )
 
-type wincred struct{}
-
-// New creates a new wincred.
-func New() credentials.Helper {
-	return wincred{}
-}
+// Wincred handles secrets using the Windows credential service.
+type Wincred struct{}
 
 // Add adds new credentials to the windows credentials manager.
-func (h wincred) Add(creds *credentials.Credentials) error {
+func (h Wincred) Add(creds *credentials.Credentials) error {
 	g := winc.NewGenericCredential(creds.ServerURL)
 	g.UserName = creds.Username
 	g.CredentialBlob = []byte(creds.Secret)
@@ -22,7 +18,7 @@ func (h wincred) Add(creds *credentials.Credentials) error {
 }
 
 // Delete removes credentials from the windows credentials manager.
-func (h wincred) Delete(serverURL string) error {
+func (h Wincred) Delete(serverURL string) error {
 	g, err := winc.GetGenericCredential(serverURL)
 	if g == nil {
 		return nil
@@ -34,7 +30,7 @@ func (h wincred) Delete(serverURL string) error {
 }
 
 // Get retrieves credentials from the windows credentials manager.
-func (h wincred) Get(serverURL string) (string, string, error) {
+func (h Wincred) Get(serverURL string) (string, string, error) {
 	g, _ := winc.GetGenericCredential(serverURL)
 	if g == nil {
 		return "", "", credentials.ErrCredentialsNotFound

wincred/wincred_windows_test.go

@@ -13,7 +13,7 @@ func TestWinCredHelper(t *testing.T) {
 		Secret:    "foobarbaz",
 	}
 
-	helper := New()
+	helper := Wincred{}
 	if err := helper.Add(creds); err != nil {
 		t.Fatal(err)
 	}
@@ -37,7 +37,7 @@ func TestWinCredHelper(t *testing.T) {
 }
 
 func TestMissingCredentials(t *testing.T) {
-	helper := New()
+	helper := Wincred{}
 	_, _, err := helper.Get("https://adsfasdf.wrewerwer.com/asdfsdddd")
 	if err != credentials.ErrCredentialsNotFound {
 		t.Fatalf("exptected ErrCredentialsNotFound, got %v", err)