That's your job to do such a thing, using a sf::View. Attach a camera to a entity is highly dependent on your ame engine.
I've a class Camera that can turn or translate over time but I've to re write it wih the new SFML conventions, and this class is very easy to implement by yoursef (You only need to store the angle or position target, one or two boleeans, the speed and update the camera at each loop)
