Update endpoint for add an uploaded file to an existing artifact

Author: wissem

README.md

@@ -609,10 +609,10 @@ $client->packages()->editArtifactPackage('acme-website/package', $artifactFileId
 #### Add an artifact file to an existing package
 
 ```php
-$packageId = 1;
+$packageName = 'acme/artifact';
 $fileName = 'package1.zip';
 $file = file_get_contents($fileName);
-$client->packages()->artifacts()->add($packageId, $file, 'application/zip', $fileName);
+$client->packages()->artifacts()->add($packageName, $file, 'application/zip', $fileName);
 ```
 ### Credential
 

src/Api/Packages/Artifacts.php

@@ -21,9 +21,9 @@ public function create($file, $contentType, $fileName)
         ]));
     }
 
-    public function add($packageId, $file, $contentType, $fileName)
+    public function add($packageName, $file, $contentType, $fileName)
     {
-        return $this->postFile('/packages/'.$packageId.'/artifacts/', $file, array_filter([
+        return $this->postFile('/packages/'.$packageName.'/artifacts/', $file, array_filter([
             'Content-Type' => $contentType,
             'X-FILENAME' => $fileName
         ]));

tests/Api/Packages/ArtifactsTest.php

@@ -37,7 +37,7 @@ public function testCreate()
 
     public function testAdd()
     {
-        $packageId = 10;
+        $packageName = 'acme/artifact';
         $expected = [
             'id' => 1,
         ];
@@ -51,11 +51,11 @@ public function testAdd()
         $api = $this->getApiMock();
         $api->expects($this->once())
             ->method('postFile')
-            ->with($this->equalTo('/packages/'.$packageId.'/artifacts/'), $rawFileContent, $headers)
+            ->with($this->equalTo('/packages/'.$packageName.'/artifacts/'), $rawFileContent, $headers)
             ->willReturn($expected);
 
 
-        $this->assertSame($expected, $api->add($packageId,$rawFileContent, $headers['Content-Type'], $headers['X-FILENAME']));
+        $this->assertSame($expected, $api->add($packageName,$rawFileContent, $headers['Content-Type'], $headers['X-FILENAME']));
     }
 
     public function testShow()