Fix ansible & shell errors

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

Change-Id: Icf63ca02469f2ceb377b4ceb42bdc3004325dbd7
diff --git a/roles/remove-artifacts-from-executor/tasks/main.yaml b/roles/remove-artifacts-from-executor/tasks/main.yaml
new file mode 100644
index 0000000..5d1dad8
--- /dev/null
+++ b/roles/remove-artifacts-from-executor/tasks/main.yaml
@@ -0,0 +1,9 @@
+- fail:
+    msg: "This role only works in the 'promote' pipeline."
+  when: zuul.pipeline != 'promote'
+
+- name: Nuke artifacts directory on executor as it is not needed anymore
+  delegate_to: localhost
+  file:
+    path: "{{ zuul.executor.work_root }}/artifacts"
+    state: absent