[@AtomicNut]

Having done some more reading you are correct, photos do not have mass. However, they can contribute to the mass of an object.

If you were to create a box lined with mirrors and light were to be reflected constantly back and forth within this box then the mass of the box would increase if light were to be added to it. 

Photons possess a nonvariant mass of 0. However, they possess a nonzero relativistic mass.

TLDR: Light is weird.