Fixes based on scrutinizer recommendations.

Author: irazasyed

src/TelegramFile.php

@@ -70,7 +70,7 @@ public function file($file, string $type, string $filename = null): self
             'contents' => (is_file($file) && is_readable($file)) ? fopen($file, 'rb') : $file,
         ];
 
-        if ($filename) {
+        if ($filename !== null) {
             $this->payload['file']['filename'] = $filename;
         }
 

src/Traits/HasSharedLogic.php

@@ -40,8 +40,9 @@ public function button($text, $url, $columns = 2): self
     {
         $this->buttons[] = compact('text', 'url');
 
-        $replyMarkup['inline_keyboard'] = array_chunk($this->buttons, $columns);
-        $this->payload['reply_markup'] = json_encode($replyMarkup);
+        $this->payload['reply_markup'] = json_encode([
+            'inline_keyboard' => array_chunk($this->buttons, $columns),
+        ]);
 
         return $this;
     }