Installer fails when proxy requires authentication #245
Description
Subject
When using a proxy which requires authentication, the installer fails with an error.
This is due to the fact that the installer does not set the authentication header.
Steps to reproduce
Configure a proxy via the environmental variables with a username and password
Expected results
Installer works.
Actual results
Error message:
!! In CKEditorInstaller.php line 336:
!!
!! Unable to download CKEditor ZIP archive from "https://github.com/ckeditor/ckeditor-releases/archive/full/latest.zip
!! ". (file_get_contents(https://github.com/ckeditor/ckeditor-releases/archive/full/latest.zip): failed to open stream
!! : Cannot connect to HTTPS server through proxy)