D8 - Using Composer to download git repo I want to download my libraries (/libraries) via composer.

Content of my composer.json:

 "repositories": [
    {
        "type": "composer",
        "url": "https://packages.drupal.org/8"
    },
    {
        "type": "github",
        "url": "https://github.com/w8tcha/CKEditor-CodeMirror-Plugin.git"
    }
]


I call composer require "w8tcha/CKEditor-CodeMirror-Plugin":"*"

which tells me

Error -  The requested package w8tcha/ckeditor-codemirror-plugin could not be found in any version, there may be a typo in the package name.


What I am doing wrong?

Thanks
As per @igorw's answer  

{
        "repositories": [
            {
                "url": "https://github.com/w8tcha/CKEditor-CodeMirror-Plugin/blob/master/composer.json",
                "type": "git"
            }
        ],
        "require": {
            "ckeditor-codemirror-plugin": "~1.17.2"
        }

}


Then type


  composer require "ckeditor-codemirror-plugin":"1.17.2"