Use window.prompt to confirm board deletion
Use window.prompt to confirm board deletion

- Closes #1778

mrniaboc/Panoptes-Front-End,amyrebecca/Panoptes-Front-End,amyrebecca/Panoptes-Front-End,amyrebecca/Panoptes-Front-End,alexbfree/Panoptes-Front-End,jelliotartz/Panoptes-Front-End,mrniaboc/Panoptes-Front-End,jelliotartz/Panoptes-Front-End,parrish/Panoptes-Front-End,CKrawczyk/Panoptes-Front-End,CKrawczyk/Panoptes-Front-End,alexbfree/Panoptes-Front-End,parrish/Panoptes-Front-End,mrniaboc/Panoptes-Front-End,CKrawczyk/Panoptes-Front-End,fmnhExhibits/Panoptes-Front-End,jelliotartz/Panoptes-Front-End,fmnhExhibits/Panoptes-Front-End,alexbfree/Panoptes-Front-End,zooniverse/Panoptes-Front-End,parrish/Panoptes-Front-End,fmnhExhibits/Panoptes-Front-End