To expand @Astrotronic setup, here is one with the Linear Gradient included:
And depending on which output from the Gradient you use, you can switch between left-right movement, or up-down movement - wich then can speed up or changed in the direction with the Speed value, that you feed into the panner. Positive numbers go one way, negative numbers go the other way.
Edit: Just for fun, with switching out some nodes, you also can create a cool scanline effect 
Be warned about the insane intensity, that those Color Dodge nodes create, i had to throw in that power node to heavily tone the intensity down, maybe a clamp node should be added too, to limit the max glow intensity:
