dl: add go1.12.11 and go1.13.2

Fixes golang/go#34963

Change-Id: Ie979446378f3ac41f62f15454d4b050e325c2b18
GitHub-Last-Rev: c1dde39a42cea8a2e6a05868de534ce8653f3634
GitHub-Pull-Request: golang/dl#5
Reviewed-on: https://go-review.googlesource.com/c/dl/+/201741
Reviewed-by: Filippo Valsorda <filippo@golang.org>
2 files changed