Test for failure_reason in job webhook

spec/lib/gitlab/data_builder/build_spec.rb

@@ -15,6 +15,7 @@ describe Gitlab::DataBuilder::Build do
     it { expect(data[:build_id]).to eq(build.id) }
     it { expect(data[:build_status]).to eq(build.status) }
     it { expect(data[:build_allow_failure]).to eq(false) }
+    it { expect(data[:build_failure_reason]).to eq(build.failure_reason) }
     it { expect(data[:project_id]).to eq(build.project.id) }
     it { expect(data[:project_name]).to eq(build.project.full_name) }