Allow Image::remove to be called on a "null" image

src/Eloquent/Image.php

@@ -208,9 +208,6 @@ public function isFullyRemoved()
 
     public function remove()
     {
-        if ($this->path == '') {
-            throw new \RuntimeException('Called remove on an image that has no path');
-        }
         $this->exists = false;
         $this->flush = true;
         $this->removeAtPathOnFlush = $this->path;
@@ -286,4 +283,4 @@ public function __clone()
     {
         $this->metadata = clone $this->metadata;
     }
-}
+}

tests/Unit/Eloquent/ImageTest.php

@@ -0,0 +1,44 @@
+<?php
+
+namespace ZiffDavis\Laravel\EloquentImagery\Test\Unit\Eloquent;
+
+use App\Console\Kernel;
+use PHPUnit\Framework\TestCase;
+
+class EloquentImageryObserverTest extends TestCase
+{
+    public function setup()
+    {
+        $app = require __DIR__ . '/../../../vendor/laravel/laravel/bootstrap/app.php';
+        $app->make(Kernel::class)->bootstrap();
+    }
+
+    public function testRemoveCanBeCalledMultipleTimes()
+    {
+        $foo = new TestAssets\FooModel();
+        $foo->image->setStateProperties([
+            'path' => 'foo/bar.jpg',
+            'extension' => 'jpg',
+            'width' => 1,
+            'height' => 1,
+            'hash' => '1234',
+            'timestamp' => 12345,
+            'metadata' => []
+        ]);
+        $foo->image->remove();
+        $foo->image->remove();
+
+        $expected = [
+            "path" => "",
+            "extension" => "",
+            "width" => null,
+            "height" => null,
+            "hash" => "",
+            "timestamp" => 0,
+            "metadata" => []
+        ];
+
+        $this->assertSame($expected, $foo->image->getStateProperties());
+    }
+}
+