Remove implied ARIA properties from <input type="range">

[kirsty-hames]

Subject of the issue

Mozilla ARIA slider role best practice states HTML's implicitly has the role of slider. Do not use aria-valuemax or aria-valuemin attributes on elements; use min and max instead. Otherwise, any global aria-* attributes and any other aria-* attributes applicable to the slider role.

See Slider issue for discussion thread - adaptlearning/adapt-contrib-slider#191