finish acceptance tests and refactor IotaCodesClient to service container

app/Libraries/IotaCodes/IotaCodesServiceProvider.php

@@ -0,0 +1,20 @@
+<?php
+
+namespace App\Libraries\IotaCodes;
+
+use Illuminate\Support\ServiceProvider;
+
+class IotaCodesServiceProvider extends ServiceProvider
+{
+    /**
+     * Register any application services.
+     *
+     * @return void
+     */
+    public function register()
+    {
+        $this->app->singleton('IotaCodesClient', function ($app) {
+            return Client::create();
+        });
+    }
+}