future-private: add change margin mode request

src/LaravelBitunixApiServiceProvider.php

@@ -4,6 +4,7 @@ namespace Msr\LaravelBitunixApi;
 
 use Msr\LaravelBitunixApi\Commands\LaravelBitunixApiCommand;
 use Msr\LaravelBitunixApi\Requests\ChangeLeverageRequestContract;
+use Msr\LaravelBitunixApi\Requests\ChangeMarginModeRequestContract;
 use Msr\LaravelBitunixApi\Requests\FutureKLineRequestContract;
 use Spatie\LaravelPackageTools\Package;
 use Spatie\LaravelPackageTools\PackageServiceProvider;
@@ -31,5 +32,6 @@ class LaravelBitunixApiServiceProvider extends PackageServiceProvider
 
         $this->app->bind(FutureKLineRequestContract::class, LaravelBitunixApi::class);
         $this->app->bind(ChangeLeverageRequestContract::class, LaravelBitunixApi::class);
+        $this->app->bind(ChangeMarginModeRequestContract::class, LaravelBitunixApi::class);
     }
 }