Set up Zuul check pipeline

Fixed: translateselectedtext:3
Change-Id: Ifcb104b3f4985240a89b3e59e919fa2e950ce497
diff --git a/roles/build-extension/defaults/main.yaml b/roles/build-extension/defaults/main.yaml
new file mode 100644
index 0000000..2774de6
--- /dev/null
+++ b/roles/build-extension/defaults/main.yaml
@@ -0,0 +1 @@
+make_target: chromium_stable