Patches based on upstream patch below but reworked to apply to 5.0.0

From 299e0ddbb8fcafc99214c26d6002da145cc84a0c Mon Sep 17 00:00:00 2001
From: Sergei Trofimovich <slyfox@gentoo.org>
Date: Sun, 18 Mar 2018 21:13:09 +0000
Subject: [PATCH] rbnacl: fix byffer size type in randombytes_buf binding

---
 lib/rbnacl/random.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/rbnacl/random.rb b/lib/rbnacl/random.rb
index 9742186..db85d6d 100644
--- a/lib/rbnacl/random.rb
+++ b/lib/rbnacl/random.rb
@@ -13,7 +13,7 @@ module Random
 
     sodium_function :c_random_bytes,
                     :randombytes_buf,
-                    [:pointer, :ulong_long]
+                    %i[pointer size_t]
 
     # Returns a string of random bytes
     #