Add test for the too big upload fail

upload/upload_test.go

@@ -66,4 +66,7 @@ func TestTooBigUpload(t *testing.T) {
 	} else if err.Error() != "received 413 - file too large" {
 		t.Errorf("wrong error occurred: %s", err.Error())
 	}
+	if u.Failed != true {
+		t.Error("upload should have been marked failed")
+	}
 }