update header according to cppyy-backend (#104)

Author: Vipul-Cariappa

src/Cppyy.h

@@ -327,7 +327,8 @@ namespace Cppyy {
     TCppType_t  GetType(const std::string& name, bool enable_slow_lookup = false);
     CPPYY_IMPORT
     bool AppendTypesSlow(const std::string &name,
-                         std::vector<Cpp::TemplateArgInfo>& types);
+                         std::vector<Cpp::TemplateArgInfo>& types,
+                         TCppScope_t parent = nullptr);
     CPPYY_IMPORT
     TCppType_t  GetComplexType(const std::string& element_type);
     CPPYY_IMPORT