Add CallCredentials class to Ruby wrapping code
diff --git a/src/ruby/ext/grpc/rb_grpc.c b/src/ruby/ext/grpc/rb_grpc.c
index 7c7c2d3..b4b7044 100644
--- a/src/ruby/ext/grpc/rb_grpc.c
+++ b/src/ruby/ext/grpc/rb_grpc.c
@@ -41,6 +41,7 @@
 #include <grpc/grpc.h>
 #include <grpc/support/time.h>
 #include "rb_call.h"
+#include "rb_call_credentials.h"
 #include "rb_channel.h"
 #include "rb_channel_credentials.h"
 #include "rb_completion_queue.h"
@@ -318,6 +319,7 @@
   Init_grpc_channel();
   Init_grpc_completion_queue();
   Init_grpc_call();
+  Init_grpc_call_credentials();
   Init_grpc_channel_credentials();
   Init_grpc_server();
   Init_grpc_server_credentials();