Make Danger as for backend review for .gitlab-ci.yml

Signed-off-by: Rémy Coutable <remy@rymai.me>

lib/gitlab/danger/helper.rb

@@ -114,7 +114,7 @@ module Gitlab
         %r{\A(ee/)?spec/(?!javascripts)[^/]+} => :backend,
         %r{\A(ee/)?vendor/(?!assets)[^/]+} => :backend,
         %r{\A(ee/)?vendor/(languages\.yml|licenses\.csv)\z} => :backend,
-        %r{\A(Dangerfile|Gemfile|Gemfile.lock|Procfile|Rakefile)\z} => :backend,
+        %r{\A(Dangerfile|Gemfile|Gemfile.lock|Procfile|Rakefile|\.gitlab-ci\.yml)\z} => :backend,
         %r{\A[A-Z_]+_VERSION\z} => :backend,
 
         %r{\A(ee/)?db/} => :database,

spec/lib/gitlab/danger/helper_spec.rb

@@ -249,6 +249,7 @@ describe Gitlab::Danger::Helper do
       'Gemfile.lock'   | :backend
       'Procfile'       | :backend
       'Rakefile'       | :backend
+      '.gitlab-ci.yml' | :backend
       'FOO_VERSION'    | :backend
 
       'ee/FOO_VERSION' | :unknown