Fix ansible & shell errors

Oh the joy of multi-step implement-run-debug situations like this...

Change-Id: Icf63ca02469f2ceb377b4ceb42bdc3004325dbd7
diff --git a/roles/return-built-artifact/defaults/main.yaml b/roles/return-built-artifact/defaults/main.yaml
index f822316..d419ead 100644
--- a/roles/return-built-artifact/defaults/main.yaml
+++ b/roles/return-built-artifact/defaults/main.yaml
@@ -1 +1,2 @@
 artifacts: []
+zuul_output_dir: "{{ ansible_user_dir }}/zuul-output"