Add new amp-analytics vendor: Keen

[adamkasprowicz]

related issue #19359

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[adamkasprowicz]

I signed it!

[googlebot]

CLAs look good, thanks!

[torch2424]

Hello! Thanks for making an intent to implement issue and opening a PR to add yourself! 😄

I noticed that you are still committing to the PR. Please mention me (@) whenever this is ready, and we can do a review.

Thank you!

[torch2424]

Oh wait just realized you were just fixing tests and things, will review this now!

[torch2424]

LGTM Waiting on @zhouyx response to get this merged in.

Also, went ahead and tested this, and everything looks fine 😄

[torch2424]

Thanks for fixing these line endings for us! Didn't catch those last time.

[torch2424]

@zhouyx Could you remind me about how the transport works ( especially what to check for image ? )

[adamkasprowicz]

@torch2424 in our case transport called "image" wouldn't work, because we need to receive Post Body content in our API.
Some people want to track "clicks", so we need to rely on the BeaconAPI (to run requests in background).

[zhouyx]

@adamkasprowicz What about browsers that don't support BeaconAPI, do you want to fallback to using xhrpost?

[adamkasprowicz]

@zhouyx yes, xhrpost also works for us - I changed the config value to True.

[zhouyx]

Thank you. LGTM

[torch2424]

Everyone LGTM'd Merging 😄

Also, you probably want to also add yourself to our docs site for supported analytics vendors: https://github.com/ampproject/docs/tree/master/content/docs/analytics

Thanks for the PR!