* WIP
* Add ability to filter by anything
* Add API keys
* Add version to api endpoint
* Fix API test route
* Fix API tests
* Allow 'date' parameter in '6mo' and '12mo'
* Rename session -> visit in API filters
* Filter expressions in the API
* Implement filters in aggregate call
* Add `compare` option to aggregate call
* Add way to manage API keys through the UI
* Authenticate with API key
* Use API key in tests
