(jobs) support `pipeline` in jobs response

Ref: https://docs.gitlab.com/ce/api/jobs.html#get-a-single-job

jobs.go

@@ -46,6 +46,12 @@ type Job struct {
 	FinishedAt *time.Time `json:"finished_at"`
 	ID         int        `json:"id"`
 	Name       string     `json:"name"`
+	Pipeline   struct {
+		ID     int    `json:"id"`
+		Ref    string `json:"ref"`
+		Sha    string `json:"sha"`
+		Status string `json:"status"`
+	} `json:"pipeline"`
 	Ref    string `json:"ref"`
 	Runner struct {
 		ID          int    `json:"id"`