Expand tests, do code cleanup.

app/Import/Object/ImportCategory.php

@@ -28,6 +28,9 @@ use FireflyIII\User;
 use Illuminate\Support\Collection;
 use Log;
 
+/**
+ * Class ImportCategory
+ */
 class ImportCategory
 {
     /** @var Category */

app/Import/Object/ImportCurrency.php

@@ -27,6 +27,9 @@ use FireflyIII\Repositories\Currency\CurrencyRepositoryInterface;
 use FireflyIII\User;
 use Log;
 
+/**
+ * Class ImportCurrency
+ */
 class ImportCurrency
 {
     /** @var array */