Add the Ericsson GUS/2015 slide deck

The presentation made by Frank Stockmans in 2015
about the Ericsson migration to Gerrit was *very interesting*
and thus is worth to be shared for the people of the community
to review and learn from it.

Change-Id: Ic3548939962c5e6e57620406b22a15d755b126b5

sat.md

diff --git a/sat.md b/sat.md
index e27bc7f..b48e14d 100644
--- a/sat.md
+++ b/sat.md
@@ -100,6 +100,8 @@
 
 *Frank Stockmans, Ericsson*
 
+[Slides](https://drive.google.com/open?id=1-BZBBIpnR6THOHE0mKyVOvRNXPH-sFKp)
+
 ## 3:00 pm Gerrit at Yahoo, a 2-year Journey
 
 Sharing our experience in these 2 years on Gerrit's growth in Yahoo