The Network shuts down after a few minutes, are you trying it right after?
Also, are you running on a raspberry pi 3 or 2?
So far on the 2 it seems initial configuration needs to happen to get it to use the network adapters.
You can manually connect it by editing the wpa_supplicant file. It should be here:
sudo nano /etc/wpa_supplicant/wpa_supplicant.conf
More info on that should be here:
Would it help if we put this info somewhere, like the wiki page for the picroft_environment github repo?