Remove upload/artifacts, we moved that to separate package

internal/upload/artifacts.go

-package upload
-
-import (
-	"../api"
-	"net/http"
-)
-
-func Artifacts(myAPI *api.API, h http.Handler) http.Handler {
-	return myAPI.PreAuthorizeHandler(func(w http.ResponseWriter, r *http.Request, a *api.Response) {
-		r.Header.Set(tempPathHeader, a.TempPath)
-		handleFileUploads(h).ServeHTTP(w, r)
-	}, "/authorize")
-}