Allow test stage tasks to retry

test-and-deploy.yml

@@ -345,6 +345,7 @@ stages:
     - ahoy test phpcs -- --report=xml --report-file=/tmp/phpcs.xml
   after_script:
     - docker cp ${COMPOSE_PROJECT_NAME}-php-1:/tmp/phpcs.xml phpcs.xml
+  retry: 1
   artifacts:
     name: phpcs
     when: always
@@ -372,6 +373,7 @@ stages:
   after_script:
     - docker cp ${COMPOSE_PROJECT_NAME}-php-1:/tmp/junit.xml junit.xml
     - docker cp ${COMPOSE_PROJECT_NAME}-php-1:/tmp/testdox.html testdox.html
+  retry: 1
   artifacts:
     name: phpunit
     when: always
@@ -424,6 +426,7 @@ stages:
     GIT_STRATEGY: none
   script:
     - backstop test
+  retry: 1
   artifacts:
     name: backstop
     when: always