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

[Jordi Mas <jmas src gnome org>]

commit d666a5f1edb0e788c63bbaba353d4ff5e895d592
Author: Jordi Mas <jmas softcatala org>
Date:   Thu May 16 08:10:33 2019 +0000

    Update .gitlab-ci.yml

 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 0c53f6a..7afad3b 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -9,7 +9,7 @@ build:
     - 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
     - apt-get install valac libvte-2.91-dev libzeitgeist-2.0-dev gedit-dev -y
-    - apt-get install python3 python3-dbus python-dbus-dev python3-gi appstream -y
+    - apt-get install python3 python3-pip python3-dbus python-dbus-dev python3-gi appstream -y
     - apt-get install meson ninja-build -y
     - python3 -m pip3 install flake8