Image Chooser Causes App Crash on iPad

[yeldarby]

Looks like there's one more step to getting this to work on iPad. I'll submit a pull request to fix this issue when I figure it out.

2017-07-09 14:20:36.755971-0500 HelloVision[476:34377] *** Terminating app due to uncaught exception 'NSGenericException', reason: 'Your application has presented a UIAlertController (<UIAlertController: 0x103822600>) of style UIAlertControllerStyleActionSheet. The modalPresentationStyle of a UIAlertController with this style is UIModalPresentationPopover. You must provide location information for this popover through the alert controller's popoverPresentationController. You must provide either a sourceView and sourceRect or a barButtonItem. If this information is not known when you present the alert controller, you may provide it in the UIPopoverPresentationControllerDelegate method -prepareForPopoverPresentation.'