The upload handler should use stream wrappers

This would need a re-roll, than we can continue.

worked together with michaellenahan and Thomas Schuh at dcmuc16.

We did a reroll and the update hook. Here is the pull request: https://github.com/drupal-media/dropzonejs/pull/35
Unfortunately the travis test failed so we gonna fix that test Drupal\Tests\dropzonejs\Kernel\DropzoneJsUploadControllerTest::testDropzoneJsUploadController

this is the failing patch

We found the reason for the test failing. We need to do the installConfig see some examples here: https://api.drupal.org/api/drupal/core%21tests%21Drupal%21KernelTests%21...
It seems that the KernelTest needs to be told about the configuration.

The test pass in php but ont in hhvm. See https://travis-ci.org/drupal-media/dropzonejs/builds/180464022

updated patch with working test file

This patch needed a re-roll

Just two things:

I found one other instance of tmp_dir:
src/Element/DropzoneJs.php:139: $tmp_override = \Drupal::config('dropzonejs.settings')->get('tmp_dir');

+++ b/config/install/dropzonejs.settings.yml
@@ -1 +1 @@
+upload_scheme: temporary

I am not sure about naming this upload_scheme, from that we do not actually know that we are configuring the temporary upload location. Maybe tmp_upload_scheme?

Addressed the comments from #13

Committed and pushed.

Thanks everyone.