Refactor Network and create Metrics class

src/Network.h

@@ -15,6 +15,7 @@ namespace bayesnet {
         vector<string> features;
         string className;
         int laplaceSmoothing;
+        torch::Tensor samples;
         bool isCyclic(const std::string&, std::unordered_set<std::string>&, std::unordered_set<std::string>&);
         vector<double> predict_sample(const vector<int>&);
         vector<double> exactInference(map<string, int>&);
@@ -24,12 +25,12 @@ namespace bayesnet {
         double conditionalEntropy(torch::Tensor&, torch::Tensor&);
         double mutualInformation(torch::Tensor&, torch::Tensor&);
     public:
-        torch::Tensor samples;
         Network();
         Network(float, int);
         Network(float);
         Network(Network&);
         ~Network();
+        torch::Tensor& getSamples();
         float getmaxThreads();
         void addNode(string, int);
         void addEdge(const string, const string);