Continuous integration build option

src/freedombone-image

 USERNAME="$USER"
 PASSWORD=
 
+CONTINUOUS_INTEGRATION=
+
 # IP address of the router (gateway)
 ROUTER_IP_ADDRESS="192.168.1.254"
 
             shift
             INTERACTIVE="$1"
             ;;
+        --ci)
+            shift
+            CONTINUOUS_INTEGRATION="$1"
+            ;;
         -g|--generic)
             shift
             GENERIC_IMAGE="$1"
      AMNESIC="$AMNESIC" \
      SOCIALINSTANCE="$SOCIALINSTANCE" \
      EXTERNAL_DRIVE="$EXTERNAL_DRIVE" \
+     CONTINUOUS_INTEGRATION="$CONTINUOUS_INTEGRATION" \
      LOCAL_NAME="$LOCAL_NAME"
 
 # shellcheck disable=SC2181

src/freedombone-image-customise

 BMX7_REPO="https://github.com/bmx-routing/bmx7"
 BMX7_COMMIT='0a82c7c10fef44b259b35e77ab33632aa132d219'
 
+CONTINUOUS_INTEGRATION=
+
 PATH=/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin
 
 # Whether to use a SATA drive and if so what its device/partition name is

src/freedombone-image-make

 export SOCIALINSTANCE
 export LOCAL_NAME
 export EXTERNAL_DRIVE
+export CONTINUOUS_INTEGRATION
 
 # Locate vmdebootstrap program fetched in Makefile
 basedir=`pwd`
 sed -i "s|LOCAL_NAME=.*|LOCAL_NAME=\"${LOCAL_NAME}\"|g" "$TEMP_CUSTOMISE3"
 sed -i "s|EXTERNAL_DRIVE=.*|EXTERNAL_DRIVE=\"${EXTERNAL_DRIVE}\"|g" "$TEMP_CUSTOMISE3"
 sed -i 's|#!/bin/bash||g' "$TEMP_CUSTOMISE3"
+sed -i "s|CONTINUOUS_INTEGRATION=.*|CONTINUOUS_INTEGRATION=${CONTINUOUS_INTEGRATION}|g" "$TEMP_CUSTOMISE3"
 
 cat $TEMP_CUSTOMISE2 $TEMP_CUSTOMISE3 > $TEMP_CUSTOMISE4
 if [ -f $TEMP_CUSTOMISE ]; then

src/freedombone-image-makefile

 ARCHIVE = $(IMAGE).xz
 SIGNATURE = $(ARCHIVE).sig
 OWNER = 1000
-XZ = xz --no-warn --verbose --keep --threads=0 -3
-SIGN = -gpg --output $(SIGNATURE) --detach-sig $(ARCHIVE)
+if [ ! "$CONTINUOUS_INTEGRATION" ];
+    XZ = xz --no-warn --verbose --keep --threads=0 -3
+    SIGN = -gpg --output $(SIGNATURE) --detach-sig $(ARCHIVE)
+fi
 
 # settings for `make test`
 TEST_SSH_PORT = 2222