Implement currency exchange rate API.

app/Models/CurrencyExchangeRate.php

@@ -22,12 +22,21 @@ declare(strict_types=1);
 
 namespace FireflyIII\Models;
 
+use Carbon\Carbon;
 use FireflyIII\User;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
 
 /**
  * Class CurrencyExchange.
+ *
+ * @property int                 $id
+ * @property Carbon              $created_at
+ * @property Carbon              $updated_at
+ * @property TransactionCurrency $fromCurrency
+ * @property TransactionCurrency $toCurrency
+ * @property float               $rate
+ *
  */
 class CurrencyExchangeRate extends Model
 {

app/Models/TransactionCurrency.php

@@ -32,6 +32,7 @@ use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
  * @property string $code
  * @property string $symbol
  * @property int    $decimal_places
+ * @property int $id
  *
  */
 class TransactionCurrency extends Model