[tracker-oci-images/sam/docker-in-docker-fix] Fix issue with latest docker-in-docker image

[Sam Thursfield <sthursfield src gnome org>]

commit a83481c505a3118570a4c2766d8240b85ca79d22
Author: Sam Thursfield <sam afuera me uk>
Date:   Wed Dec 11 12:24:36 2019 +0100

    Fix issue with latest docker-in-docker image
    
    See this blog post for details:
    https://about.gitlab.com/blog/2019/07/31/docker-in-docker-with-docker-19-dot-03/

 .gitlab-ci.yml | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index d291b3b..84ab601 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,11 +1,12 @@
-image: docker:latest
+image: docker:19.03.0
 services:
-    - docker:dind
+    - docker:19.03.0-dind
 
 # When using dind, it's wise to use the overlayfs driver for
 # improved performance.
 variables:
     DOCKER_DRIVER: overlay2
+    DOCKER_TLS_CERTDIR: "/certs"
 
 stages:
     - distro