Get a ping for every sign-up, sale and error

Add Tinyping push notifications to this project. 1. Read TINYPING_TOKEN from an environment variable and add it to the env example file. I copy it from my project page in Tinyping. 2. Create a notify(event) helper that sends a POST request to https://api.tinyping.app/v1/events with the headers "Authorization: Bearer TINYPING_TOKEN" and "Content-Type: application/json". 3. The JSON body has a required title (up to 120 characters) and an optional body (up to 2,000), url, priority (one of low, normal, high), kind (up to 40) and tags (up to 8). 4. Call notify on new sign-ups, successful payments and unhandled server errors, with a short title and the key detail in the body. 5. notify must never break the app: use a 5 second timeout, catch errors and return true or false. 6. Show me where you added the calls, then send one test event.