Setting DELTA_ENDPOINT as meta-resin does allows the dev dind supervisor to use the correct
delta server.
Inserting a VARIANT_ID into /etc/os-release allows treating this device as a dev build of Resin OS
(and avoids an unhandled exception).
Changing the precedence for device/provisioning apikeys in the vpn-init script allows the device
to connect to the VPN when a key exchange is still pending (as meta-resin does - though this is getting
replaced by watching config.json for changes).
This at least makes the development supervisor functional for now, but I'll work on improving the dind setup soon.
Change-Type: patch
Signed-off-by: Pablo Carranza Velez <pablo@resin.io>