Utility: update filter unit tests with decoupling test.

Tests/filters.cpp

@@ -123,6 +123,19 @@ TEST_CASE("Two filters can be linked together.")
       REQUIRE(high_pass.currentValue() == 46);
     }
   }
+
+  SECTION("Decoupling filters works as expected.")
+  {
+    high_pass.update(60);
+    REQUIRE(high_pass.currentValue() == 0);
+
+    high_pass.clearPrecedingFilter();
+    high_pass.update(60);
+    REQUIRE(high_pass.currentValue() == 60);
+
+    high_pass.update(30);
+    REQUIRE(high_pass.currentValue() == 60);
+  }
 }
 
 TEST_CASE("Median filter works as expected.")

Utility/Inc/utility_ifilter.hpp

@@ -12,7 +12,7 @@ template<typename T>
 class IFilter
 {
 public:
-  virtual ~IFilter() {}
+  virtual ~IFilter() = default;
 
   void assignPrecedingFilter(IFilter<T>& filter)
   {