Update travis file adding missing images

.travis.yml

@@ -10,20 +10,34 @@ env:
 - DOCKER_IMAGE=php/php53-debug
 - DOCKER_IMAGE=php/php54
 - DOCKER_IMAGE=php/php54-debug
+- DOCKER_IMAGE=php/php54-cron
 - DOCKER_IMAGE=php/php55
 - DOCKER_IMAGE=php/php55-debug
+- DOCKER_IMAGE=php/php55-cron
 - DOCKER_IMAGE=php/php56
 - DOCKER_IMAGE=php/php56-debug
+- DOCKER_IMAGE=php/php56-cron
 - DOCKER_IMAGE=php/php70
 - DOCKER_IMAGE=php/php70-debug
+- DOCKER_IMAGE=php/php70-cron
 - DOCKER_IMAGE=php/php71
 - DOCKER_IMAGE=php/php71-debug
+- DOCKER_IMAGE=php/php71-cron
 - DOCKER_IMAGE=php/php72
 - DOCKER_IMAGE=php/php72-debug
+- DOCKER_IMAGE=php/php72-cron
 - DOCKER_IMAGE=php/php73
 - DOCKER_IMAGE=php/php73-debug
+- DOCKER_IMAGE=php/php73-cron
 - DOCKER_IMAGE=php/php74
 - DOCKER_IMAGE=php/php74-debug
+- DOCKER_IMAGE=php/php74-cron
+- DOCKER_IMAGE=php/php80
+- DOCKER_IMAGE=php/php80-debug
+- DOCKER_IMAGE=php/php80-cron
+- DOCKER_IMAGE=php/php81
+- DOCKER_IMAGE=php/php81-debug
+- DOCKER_IMAGE=php/php81-cron
 
 services:
 - docker
@@ -32,7 +46,7 @@ install:
 - docker build -t ${DOCKER_IMAGE/\//-} $DOCKER_IMAGE
 - docker run --rm -d --name ${DOCKER_IMAGE/\//-} ${DOCKER_IMAGE/\//-}
 
-before_script:
+before_script: skip
 
 script:
 - docker ps | grep -q ${DOCKER_IMAGE/\//-}