Unity3D flat image scrolling skybox?

I want the skybox in my game to be a flat image that is locked to the y-axis and scrolls along the x-axis. (E.g., vertical camera movement results in no change while horizontal camera movement results in the sky panning with the camera.) I have a texture which tiles seamlessly, but I'm looking for a shader or something of the like to achieve what I want.

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Edit: I found code for a flat texture shader on GitHub. Now I only need for the texture to pan with the camera.