Genymotion virtual devices are all rooted and it is not possible to unroot them for the moment. However, we are aware that this is a popular feature and non-rooted devices will be available in the future.
To help us in this task, feel free to fill our feature request form at https://forms.gle/1jsegyt4xr33Mt3z6.
In the meantime, it is possible to hide root from an application in some cases: