Switch default Ubuntu distribution to bionic.
Switch default Ubuntu distribution to bionic.

OSGeo/OSGeoLive,OSGeo/OSGeoLive,kalxas/OSGeoLive,astroidex/OSGeoLive,kalxas/OSGeoLive,kalxas/OSGeoLive,astroidex/OSGeoLive,kalxas/OSGeoLive,OSGeo/OSGeoLive,kalxas/OSGeoLive,OSGeo/OSGeoLive,kalxas/OSGeoLive,astroidex/OSGeoLive,OSGeo/OSGeoLive,OSGeo/OSGeoLive,astroidex/OSGeoLive,OSGeo/OSGeoLive,kalxas/OSGeoLive,astroidex/OSGeoLive,astroidex/OSGeoLive