createTicket working, solves #3

cli/include/json_serializer.h

@@ -0,0 +1,13 @@
+#include <string>
+#include <optional>
+#include <nlohmann/json.hpp>
+
+#include "ticket.h"
+
+using json = nlohmann::json;
+
+// Deserialize JSON -> class
+void from_json(const json& j, ticket_t& t);
+
+// Serialize class
+void to_json(json& j, const ticket_t& t);