[Jobs] Add options struct for DownloadArtifactsFile func which contains the job name

jobs.go

@@ -178,25 +178,26 @@ func (s *JobsService) GetJobArtifacts(pid interface{}, jobID int, options ...Opt
 	return artifactsBuf, resp, err
 }
 
+// DownloadArtifactsFileOptions represents the available DownloadArtifactsFile() options.
+//
+// GitLab API docs: https://docs.gitlab.com/ce/api/jobs.html#download-the-artifacts-file
+type DownloadArtifactsFileOptions struct {
+	Job *string `url:"job,omitempty" json:"job,omitempty"`
+}
+
 // DownloadArtifactsFile download the artifacts file from the given
 // reference name and job provided the job finished successfully.
 //
-// GitLab API docs:
-// https://docs.gitlab.com/ce/api/jobs.html#download-the-artifacts-file
-func (s *JobsService) DownloadArtifactsFile(pid interface{}, refName string, job string, options ...OptionFunc) (io.Reader, *Response, error) {
+// GitLab API docs: https://docs.gitlab.com/ce/api/jobs.html#download-the-artifacts-file
+func (s *JobsService) DownloadArtifactsFile(pid interface{}, refName string, opt *DownloadArtifactsFileOptions, options ...OptionFunc) (io.Reader, *Response, error) {
 	project, err := parseID(pid)
 	if err != nil {
 		return nil, nil, err
 	}
 
-    var q struct {
-        Job string `url:"job,omitempty" json:"job,omitempty"`
-    }
-    q.Job = job
-
 	u := fmt.Sprintf("projects/%s/jobs/artifacts/%s/download", url.QueryEscape(project), refName)
 
-	req, err := s.client.NewRequest("GET", u, q, options)
+	req, err := s.client.NewRequest("GET", u, opt, options)
 	if err != nil {
 		return nil, nil, err
 	}