Testing Unity 5 compatibility but publishing for Unity 4.x (or 3.x)

Hi, i would like to know what is the best and simple way to test the compatibility of a Unity Asset Package with Unity 5, but publishing it with Unity 4.x (or also Unity 3.x). I could create the package directly in Unity 5 and publish it from it, but i don't want it to be limited to Unity 5 users, i want that also Unity 4.x users (and, if possible, also Unity 3.x users) could use it.

So basically suppose i build a package on Unity 4 or Unity 3, then, before publishing it, i want to know if it will be compatible with Unity 5 and will not show the warning that says that the script may be incompatible when the user purchase it. There is a way to try the compatibility before publishing it, instead of send it for review to the Unity team, and wait the package to be published, then trying to purchase it and see if the "warning" message is shown ?

My assets, currently, are mainly graphics packages (models with textures and their prefabs) but sometimes contains some simple scripts which maybe incompatible with unity 5, so i would like to test them before publishing with Unity 4 or 3.

For example, one of my published package (published with Unity 4.x) shows the warning message. I tryed to import it in Unity and i've corrected the errors, now i want to send an update, but instead of publishing it with Unity 5 i want to publish again with Unity 4 so that people who doesn't have Unity 5 can use it.

Thanks!