Adds Jeff Terrace to AUTHORS

AUTHORS

@@ -64,3 +64,4 @@ Ordered by date of first contribution:
   Balachandran C <balachandran.c@gramvaani.org>
   Kevin Tran <hekevintran@gmail.com>
   Branko Čibej <brane@apache.org>
+  Jeff Terrace <jterrace@gmail.com>