session consumer query함수 리턴 값의 애매함을 제거

session/common.go

@@ -32,8 +32,8 @@ func (auth *Authorization) ToStrings() []string {
 	}
 }
 
-func (auth *Authorization) Invalidated() bool {
-	return len(auth.invalidated) > 0
+func (auth *Authorization) Valid() bool {
+	return len(auth.invalidated) == 0 && !auth.Account.IsZero()
 }
 
 func MakeAuthrizationFromStringMap(src map[string]string) Authorization {
@@ -55,7 +55,7 @@ type Provider interface {
 }
 
 type Consumer interface {
-	Query(string) (Authorization, error)
+	Query(string) Authorization
 	Touch(string) (Authorization, error)
 	IsRevoked(primitive.ObjectID) bool
 	Revoke(string)