Add abstract job attribute

Change-Id: I4ee968a8e86cea8676f1c1571ad24595efb04ea7
diff --git a/tests/fixtures/config/abstract/main.yaml b/tests/fixtures/config/abstract/main.yaml
new file mode 100644
index 0000000..208e274
--- /dev/null
+++ b/tests/fixtures/config/abstract/main.yaml
@@ -0,0 +1,8 @@
+- tenant:
+    name: tenant-one
+    source:
+      gerrit:
+        config-projects:
+          - common-config
+        untrusted-projects:
+          - org/project