Add `aria-current` to the list of valid attributes

[zmrhaljiri]

Auditing a page containing aria-current attribute, for example within a breadcrumbs component, results in the following error:

This element has an invalid ARIA attribute
https://github.com/GoogleChrome/accessibility-developer-tools/wiki/Audit-Rules#ax_aria_11
This audit rule will warn you if it finds an aria-* attribute that is not listed in the WAI-ARIA 1.0 States and Properties spec.

aria-current, however, seems to be under WAI-ARIA 1.1 and so is a valid attribute then.

Would it be possible to add it to the list of valid attributes, please?