Add canary nightly build job

Bug: translateselectedtext:10
Change-Id: I77cfaaa048a1e6a388b1d120b7070f3fa32ae632
diff --git a/playbooks/nightly-build/pre.yaml b/playbooks/nightly-build/pre.yaml
new file mode 100644
index 0000000..45db95f
--- /dev/null
+++ b/playbooks/nightly-build/pre.yaml
@@ -0,0 +1,5 @@
+- hosts: all
+  roles:
+    - role: ensure-genmanifest
+    - role: ensure-cws-upload
+      version: "2.1.0"