Available since version 1.7.1.
# Keyword arguments: grayscale, width, height
Faker::Fillmurray.image #=> "http://www.fillmurray.com/300/300"
Faker::Fillmurray.image(grayscale: true) #=> "http://fillmurray.com/g/300/300"
Faker::Fillmurray.image(grayscale: false, width: 200, height: 400) #=> "http://fillmurray.com/200/400"