Re-Add docker:dind for Packet CI (#4567)

.gitlab-ci.yml

@@ -39,6 +39,8 @@ before_script:
 
 .testcases: &testcases
   <<: *job
+  services:
+    - docker:dind
   before_script:
     - /usr/bin/python -m pip install -r tests/requirements.txt
     - mkdir -p /.ssh
@@ -52,6 +54,8 @@ before_script:
     - ls
     - echo ${PWD}
     - echo "${STARTUP_SCRIPT}"
+    # Docker is required on the ansible host for download_run_once and download_localhost
+    - docker info
     - cd tests && make create-${CI_PLATFORM} -s ; cd -
 
     # Check out latest tag if testing upgrade