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 publis$$anonymous$$ng 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 publis$$anonymous$$ng 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 publis$$anonymous$$ng 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 grap$$anonymous$$cs packages (models with textures and their prefabs) but sometimes contains some simple scripts w$$anonymous$$ch maybe incompatible with unity 5, so i would like to test them before publis$$anonymous$$ng 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 publis$$anonymous$$ng 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!