docs(testing): refer to 'lite-server' instead of 'live-server'.

[fourcube]

Since the QuickStart uses 'lite-server', the 'lite-server' module should also be used in the testing guide.

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[googlebot]

Thanks for your pull request. It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

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[fourcube]

I have just signed the CLA.

(implements #1723)

[googlebot]

CLAs look good, thanks!

[googlebot]

CLAs look good, thanks!

[Foxandxss]

Appreciated, but I don't advice spending time on the testing guide because it is going to be revamped soon.

[wardbell]

Accepting just so I have latest state before rewrite.