Add extension requirement to composer.json

[chrissound]

Ran into this issue: PHP Fatal error: Uncaught Error: Call to undefined function PHPExif\Adapter\exif_read_data() in /var/www/html/vendor/miljar/php-exif/lib/PHPExif/Adapter/Native.php:182

I think you can specify the exif extension requirement by adding ext-exif to the require object in composer.json.

[Miljar]

Good idea. Care to create a PR? :)

[djmattyg007]

If someone is using ExifTool rather than the PHP exif extension, they don't need the exif extension installed. Adding this requirement to the composer.json file would nullify this.

[Miljar]

Good point; it should be added as a suggestion