Omnibus: more automation triggers/filters/actions

[jmduke]

Trigger

• Unengaged subscriber as trigger
• New email sent
• Abandoned checkout
• Unsubscription
• Comment
• Churning
• Subscriber referral

Filtering

• Split testing (only send to 30%...)
• Geography
• Replies
• Number of referrals
• Specific Stripe products/plans

Action

• Change email audience
• Gifting/ungifting
• Unsubscribing
• Change email paywall (or lack thereof). This would allow us to create automations such as "after one year, remove the paywall from the email."
• Create Stripe customer
• (Just for Stripe/Memberful) Automatically tagging based on the product of the subscription
• Forward a reply #2704
• Retweet/repost a given ID #3469
• Remove metadata

Miscellany

• Allow marking an automation as "only once per subscriber"