Fix warnings and deprecations.

src/Random.cpp

@@ -60,7 +60,7 @@ void Random::prop_sample_bucket(
 
     // all probabilities are the same
     if (heavy == n) {
-        for (auto i = 0; i < size; ++i) {
+        for (size_t i = 0; i < size; ++i) {
             *result = (*rng)((uint64_t)n);
             ++result;
         }
@@ -121,9 +121,9 @@ void Random::prop_sample_bucket(
     }
 
     // sample
-    for (auto i = 0; i < size; ++i) {
+    for (size_t i = 0; i < size; ++i) {
         size_t bucket = (*rng)((uint64_t)n);
-        double acceptance = dqrng::uniform01((*rng)());
+        double acceptance = rng->uniform01();
         *result = (acceptance < dividing_probs[bucket]) ? bucket :
             alternative_index[bucket];
         ++result;