Add Ubuntu check

install.sh

@@ -63,7 +63,15 @@ esac
 
 echo "== Making sure python3 and virtualenv are installed =="
 python3 --version || apt-get install -y python3
-python3 -m venv -h >/dev/null 2>&1 || apt-get install -y python3-venv
+
+# Ubuntu asks for extra libraries except python3-venv. Test for other systems?
+osname=`awk -F= '/^NAME/{print $2}' /etc/os-release` 
+if [ "$osname" = '"Ubuntu"' ]; then
+   apt-get install -y python3-venv
+else
+   python3 -m venv -h >/dev/null 2>&1 || apt-get install -y python3-venv
+fi
+