support lowercase first letter properties

Author: kddejong

python/rpdk/go/templates/types.go.tple

@@ -12,7 +12,7 @@ package resource
 // {{model_name}} is autogenerated from the json schema
 type {{model_name}} struct {
 {% for name, type in properties.items() %}
-    {{ name|uppercase_first_letter }} {{ type|translate_type }} `json:",omitempty"`
+    {{ name|uppercase_first_letter }} {{ type|translate_type }} `json:"{{name}},omitempty"`
 {% endfor %}
 }