Albert Still

Results 3 issues of Albert Still

Hi, with batching enabled you flush the data on page [unload](https://github.com/mixpanel/mixpanel-js/blame/45fe840ea97c29c665022a41623d226402f4c81d/src/mixpanel-core.js#L275) which is awesome, but according to [MDN](https://developer.mozilla.org/en-US/docs/Web/API/Window/unload_event#usage_notes) `unload` should be avoided and instead the `visibilitychange` event with a `pagehide`...

Please note I don't see this issue on Android. Side note: I'm also also seeing a seperate issue that may be related to this one where by the app is...