Added alpha analytics api setup
Added alpha analytics api setup

refs https://github.com/TryGhost/Team/issues/1062

Member activity is a labs alpha feature which aims at capturing member events for site owner if switched on. The event metadata captures the site page/post where the event originates from, and the post/page id is included as content of new ghost analytics meta tag.

This change adds a new alpha API endpoint for pushing events to new ingress endpoint, which Portal's new analytics script can use to push events upstream.

TryGhost/Ghost,TryGhost/Ghost,TryGhost/Ghost