Remove empty icon

Closes #130

Author: cretueusebiu

src/WebPushMessage.php

@@ -102,7 +102,7 @@ public function title($value)
      */
     public function action($title, $action, $icon = null)
     {
-        $this->actions[] = compact('title', 'action', 'icon');
+        $this->actions[] = array_filter(compact('title', 'action', 'icon'));
 
         return $this;
     }

tests/MessageTest.php

@@ -27,6 +27,16 @@ public function title_can_be_set()
 
     /** @test */
     public function action_can_be_set()
+    {
+        $this->message->action('Some Action', 'some_action');
+
+        $this->assertEquals(
+            [['title' => 'Some Action', 'action' => 'some_action']], $this->message->toArray()['actions']
+        );
+    }
+
+    /** @test */
+    public function action_can_be_set_with_icon()
     {
         $this->message->action('Some Action', 'some_action', '/icon.png');