The IO wrapper given to exifr has to support seek modes

[julik]

since in certain situations exifr can apparently do a seek() with 2 arguments

ArgumentError::wrong number of arguments (given 2, expected 1)

/home//vendor/bundle/ruby/2.4.0/gems/format_parser-0.3.3/lib/io_constraint.rb:27:in seek' /usr/lib/ruby/2.4.0/delegate.rb:83:in method_missing'
/home//vendor/bundle/ruby/2.4.0/gems/exifr-1.3.3/lib/exifr/tiff.rb:668:in size' /home/<redacted>/vendor/bundle/ruby/2.4.0/gems/exifr-1.3.3/lib/exifr/tiff.rb:518:in next?'
/home//vendor/bundle/ruby/2.4.0/gems/exifr-1.3.3/lib/exifr/tiff.rb:522:in next' /home/<redacted>/vendor/bundle/ruby/2.4.0/gems/exifr-1.3.3/lib/exifr/tiff.rb:378:in block in initialize'
/home//vendor/bundle/ruby/2.4.0/gems/exifr-1.3.3/lib/exifr/tiff.rb:642:in open' /home/<redacted>/vendor/bundle/ruby/2.4.0/gems/exifr-1.3.3/lib/exifr/tiff.rb:376:in initialize'
/home//vendor/bundle/ruby/2.4.0/gems/format_parser-0.3.3/lib/parsers/exif_parser.rb:52:in new' /home/<redacted>/vendor/bundle/ruby/2.4.0/gems/format_parser-0.3.3/lib/parsers/exif_parser.rb:52:in scan_image_exif'
/home//vendor/bundle/ruby/2.4.0/gems/format_parser-0.3.3/lib/parsers/tiff_parser.rb:17:in call' /home/<redacted>/vendor/bundle/ruby/2.4.0/gems/format_parser-0.3.3/lib/format_parser.rb:90:in block in parse'