go.talks: add author details to "Go for gophers" slides

TBR=r
R=r
CC=golang-codereviews
https://golang.org/cl/93870043
diff --git a/2014/go4gophers.slide b/2014/go4gophers.slide
index 55d87d0..ce47430 100644
--- a/2014/go4gophers.slide
+++ b/2014/go4gophers.slide
@@ -3,6 +3,8 @@
 25 Apr 2014
 
 Andrew Gerrand
+Google, Inc.
+@enneff
 adg@golang.org
 
 
diff --git a/2014/hellogophers.slide b/2014/hellogophers.slide
index eb62e0d..0930ba5 100644
--- a/2014/hellogophers.slide
+++ b/2014/hellogophers.slide
@@ -1,5 +1,6 @@
 Hello, Gophers!
 Gophercon Opening Keynote
+24 Apr 2014
 
 Rob Pike
 Google, Inc.