added apple oauth2 integration

tools/auth/gitlab.go

@@ -1,6 +1,7 @@
 package auth
 
 import (
+	"context"
 	"encoding/json"
 	"strconv"
 
@@ -20,6 +21,7 @@ type Gitlab struct {
 // NewGitlabProvider creates new Gitlab provider instance with some defaults.
 func NewGitlabProvider() *Gitlab {
 	return &Gitlab{&baseProvider{
+		ctx:        context.Background(),
 		scopes:     []string{"read_user"},
 		authUrl:    "https://gitlab.com/oauth/authorize",
 		tokenUrl:   "https://gitlab.com/oauth/token",