THRIFT-2012: Modernize Go tooling - Fix for "make dist"

Patch: Jens Geyer
diff --git a/tutorial/go/Makefile.am b/tutorial/go/Makefile.am
index 2c2b8be..512afa3 100644
--- a/tutorial/go/Makefile.am
+++ b/tutorial/go/Makefile.am
@@ -46,6 +46,7 @@
 	$(RM) -r gen-*
 
 EXTRA_DIST = \
-	client.py \
-	handler.py \
-	server.py
+	src/client.go \
+	src/handler.go \
+	src/server.go \
+	src/main.go