add seed option

src/main.cpp

@@ -33,8 +33,13 @@ int main (const int argc, char *argv[]) {
     }
     std::cout << std::endl;
 
-    std::random_device rd;
-    std::mt19937_64 rng(rd());
+    std::mt19937_64 rng;
+    if (parameter.count("seed")) {
+        rng.seed(static_cast<uint64_t>(parameter.at("seed")));
+    } else {
+        std::random_device rd;
+        rng.seed(rd());
+    }
 
     motions::BaseMotion *motion = motions::BaseMotion::createFromInput(args.motion_type, rng);
     times::BaseDistribution *dist = times::BaseDistribution::createFromInput(args.distribution_type, rng);