Fixes#281 and #269
When elodie imports images, imghdr.what is used to determine the image
type. imghdr implementation won't support all JPEG variants. Because
of this, even for a valid JPEG file, imghdr.what returns None causing
elodie to skip the image during import.
This commit adds a fallback mechanism which uses PIL(pillow) library to
identify image formats. When imghdr fails, elodie uses pillow to
identify image format. When pillow is unavailable, it will be treated as
an invalid media file. Pillow is imported only when imghdr fails.
Jaisen Mathai