<video> elements must have an audio description track - Make it a suggestion rather than an error

[Stefany93]

Expectation: Suggest an audio description for video elements, don't flag them as errors if missing.
Actual: Flags all videos without audio descriptions

Motivation: Videos such as "talking heads", or presentations on a static background do not need audio descriptions, yet Axe spits out an error.

I have a talking head video on my website, hence no audio description needed.

Since it is impossible for axe to determine the content of the video, remove the "critical" error.

axe-core version:  (axe-core 3.3.2)
axe-webdriver, v4.0.0

Browser and Assistive Technology versions
Google Chrome 

[WilcoFiers]

Hey @Stefany93. You're absolutely right, which is why as of axe-core 3.1.0 we made this return incomplete instead of as a failure:
#1075

If you are indeed seeing this in 3.3.2, can you provide a way for us to reproduce this, because that definitely shouldn't be happening.

[straker]

Closing. Please reopen if you find this is giving a violation instead of needs review in latest version of axe.