[gedit-plugins/flake8] Update .gitlab-ci.yml

[Jordi Mas <jmas src gnome org>]

commit 2ec3f661a4fb428034d1f6816ca00f543717d16f
Author: Jordi Mas <jmas softcatala org>
Date:   Thu May 16 11:16:44 2019 +0000

    Update .gitlab-ci.yml

 .gitlab-ci.yml | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 3d0e248..c5ff38c 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -8,6 +8,7 @@ build:
   stage: build
   before_script:
     - export DEBIAN_FRONTEND=noninteractive
+    - apt-get update -y
     - apt-get install intltool yelp-tools gnome-pkg-tools libdbus-1-dev -y
     - apt-get install libgit2-glib-1.0-dev libglib2.0-dev libgtk-3-dev -y
     - apt-get install libgtksourceview-4-dev libgucharmap-2-90-dev libpeas-dev -y