Update the reduced test case starter template

[OwenEdwards]

Description

The starter template on JSBin uses http for its links even though JS Bin itself forces the URL to use https. This causes some failures.

The template also uses video.js v5, which is deprecated now; it needs updating to v6.

[gkatsev]

I created a codepen template that we can start using: https://codepen.io/gkatsev/pen/GwZegv?editors=1010#0

[gkatsev]

Made a PR for it #5570