added rng to rand call for MvTransformed

src/transformed_distribution.jl

@@ -131,7 +131,7 @@ rand(td::MvTransformed) = td.transform(rand(td.dist))
 rand(rng::AbstractRNG, td::MvTransformed) = td.transform(rand(rng, td.dist))
 # TODO: implement more efficiently for flows
 function rand(rng::AbstractRNG, td::MvTransformed, num_samples::Int)
-    res = hcat([td.transform(rand(td.dist)) for i = 1:num_samples]...)
+    res = hcat([td.transform(rand(rng, td.dist)) for i = 1:num_samples]...)
     return res
 end