init dart api server with mysql connection

lib/config.dart

@@ -0,0 +1,11 @@
+class AppConfig {
+    static const int port = 5000;
+}
+
+class DBConfig {
+    static const String dbHost = '124.54.134.127';
+    static const int dbPort = 13306;
+    static const String dbUser = 'root';
+    static const String dbPassword = '1q2w3e4r5t^Y';
+    static const String dbName = 'mess';
+}

lib/mess_api.dart

@@ -0,0 +1,3 @@
+int calculate() {
+  return 6 * 7;
+}