Add pybind caster for dict

typon/include/python/builtins/dict.hpp

@@ -6,6 +6,8 @@
 #define TYPON_DICT_HPP
 
 #include <unordered_map>
+#include <pybind11/stl.h>
+
 /*
 template <typename K, typename V>
 class PyDict : public std::unordered_map<K, V> {
@@ -134,4 +136,10 @@ private:
 
 }
 
+namespace PYBIND11_NAMESPACE {
+namespace detail {
+template <typename K, typename V>
+struct type_caster<typon::PyDict<K, V>> : map_caster<typon::PyDict<K, V>, K, V> {};
+}}
+
 #endif // TYPON_DICT_HPP