[libgda] ci: setting PostgreSQL to version 10

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit d3e770b3de799e90004e9992eead7a4724baf17e
Author: Daniel Espinosa Ortiz <esodan gmail com>
Date:   Wed Jan 9 17:17:58 2019 -0600

    ci: setting PostgreSQL to version 10
    
    There are backward incompatible changes in 11 no
    yet supported by meta data generation.

 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index c1e28ec3e..d0193bf11 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -5,7 +5,7 @@
 image: ubuntu:devel
 
 services:
-  - postgres
+  - postgres:10
 
 stages:
   - build