[ResourceManager] Make destructor virtual for use in derived classes (#1607)

Author: saikishor

hardware_interface/include/hardware_interface/resource_manager.hpp

@@ -75,7 +75,7 @@ class HARDWARE_INTERFACE_PUBLIC ResourceManager
 
   ResourceManager(const ResourceManager &) = delete;
 
-  ~ResourceManager();
+  virtual ~ResourceManager();
 
   /// Load resources from on a given URDF.
   /**