StyleCI fix

Author: petericebear

src/MessagebirdClient.php

@@ -40,7 +40,7 @@ public function send(MessagebirdMessage $message)
             $this->client->request('POST', 'https://rest.messagebird.com/messages', [
                 'body' => $message->toJson(),
                 'headers' => [
-                    'Authorization' => 'AccessKey '.$this->access_key
+                    'Authorization' => 'AccessKey '.$this->access_key,
                 ],
             ]);
         } catch (Exception $exception) {