v0.2.55..v0.2.56 changeset MeanAggregator.h

diff --git a/hoot-core/src/main/cpp/hoot/core/algorithms/aggregator/MeanAggregator.h b/hoot-core/src/main/cpp/hoot/core/algorithms/aggregator/MeanAggregator.h
index a5aebf3..bbe7873 100644
--- a/hoot-core/src/main/cpp/hoot/core/algorithms/aggregator/MeanAggregator.h
+++ b/hoot-core/src/main/cpp/hoot/core/algorithms/aggregator/MeanAggregator.h
@@ -38,7 +38,8 @@ public:
 
   static std::string className() { return "hoot::MeanAggregator"; }
 
-  MeanAggregator();
+  MeanAggregator() = default;
+  virtual ~MeanAggregator() = default;
 
   virtual double aggregate(std::vector<double>& d) const override;