[release-branch.go1.8] doc: document Go 1.8.7

Change-Id: I7ea97312bdf489c2833b1823dd633eb55f3bcd72
Reviewed-on: https://team-review.git.corp.google.com/213168
Reviewed-by: Andrew Bonventre <andybons@google.com>
diff --git a/doc/devel/release.html b/doc/devel/release.html
index 805687b..6eaddaa 100644
--- a/doc/devel/release.html
+++ b/doc/devel/release.html
@@ -87,6 +87,12 @@
 1.8.6 milestone</a> on our issue tracker for details.
 </p>
 
+<p>
+go1.8.7 (released 2018/02/07) includes a security fix to “go get”.
+See the <a href="https://github.com/golang/go/issues?q=milestone%3AGo1.8.7">Go
+1.8.7</a> milestone on our issue tracker for details.
+</p>
+
 <h2 id="go1.7">go1.7 (released 2016/08/15)</h2>
 
 <p>