dl: add go1.13

Change-Id: I1e76d4f5cb4221f58bdba59f34de168f5c88d076
Reviewed-on: https://go-review.googlesource.com/c/dl/+/192744
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
Reviewed-by: Alexander Rakoczy <alex@golang.org>
1 file changed