The reason it doesn't work is because you are running your html from a file. That means the URL scheme used for your script links is
file:
instead
http:
therefore your CDN links are resolved as
file:
which is clearly wrong.
Either connect the scheme to http: or by updating all the links to contain the scheme:
<link rel="stylesheet" type="text/css" href="http://cdn.jsdelivr.net/jquery.slick/1.3.7/slick.css"/>
or run your code from the http context, not from the file on your HD.
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