DBC now works and has a test.

builder.cpp

@@ -1,5 +1,4 @@
 #include "builder.hpp"
-#include "dbc.hpp"
 #include <chrono>                     // for milliseconds
 #include <fmt/core.h>
 #include <fstream>
@@ -15,6 +14,7 @@
 #include <fstream>
 #include <future>
 #include <mutex>
+#include "dbc.hpp"
 
 using std::string;
 using namespace fmt;