Fixed mssing virtual destructor warnings

In Visual Studio with warning 4265 enabled
Closes #844

include/internal/catch_impl.hpp

@@ -91,6 +91,7 @@ namespace Catch {
     TestSpec::NamePattern::~NamePattern() {}
     TestSpec::TagPattern::~TagPattern() {}
     TestSpec::ExcludedPattern::~ExcludedPattern() {}
+	Matchers::Impl::MatcherUntypedBase::~MatcherUntypedBase() {}
 
     void Config::dummy() {}