[geary/wip/jtojnar/no-gir] Include build-essential in Ubuntu CI package list

[Michael Gratton <mjog src gnome org>]

commit 309a3a0e9ac496859e6911f02904e5c98455efee
Author: Michael Gratton <mike vee net>
Date:   Sun Feb 24 04:39:04 2019 +0000

    Include build-essential in Ubuntu CI package list
    
    Somehow this isn't required by vala or anything else??

 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index b7e6fae0..c723cbde 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -25,7 +25,7 @@ variables:
   FEDORA_TEST_DEPS: Xvfb tar xz
 
   # Ubuntu & Debian packages
-  UBUNTU_DEPS: valac
+  UBUNTU_DEPS: valac build-essential
                meson desktop-file-utils libcanberra-dev
                libgee-0.8-dev libglib2.0-dev libgmime-2.6-dev libgtk-3-dev
                libsecret-1-dev libxml2-dev libnotify-dev libsqlite3-dev