v0.2.55..v0.2.56 changeset AverageTagMerger.h

diff --git a/hoot-core/src/main/cpp/hoot/core/schema/AverageTagMerger.h b/hoot-core/src/main/cpp/hoot/core/schema/AverageTagMerger.h
index acd243b..8c2706b 100644
--- a/hoot-core/src/main/cpp/hoot/core/schema/AverageTagMerger.h
+++ b/hoot-core/src/main/cpp/hoot/core/schema/AverageTagMerger.h
@@ -38,7 +38,8 @@ public:
 
   static std::string className() { return "hoot::AverageTagMerger"; }
 
-  AverageTagMerger();
+  AverageTagMerger() = default;
+  virtual ~AverageTagMerger() = default;
 
   virtual Tags mergeTags(const Tags& t1, const Tags& t2, ElementType et) const override;