Validate zuul_stream func test output

If we have to visually inspect the output of this test on every
run, we will fail, because we will certainly not visually inspect
the output of this test on every run. Let's at least try to
automate some of the validation.

Change-Id: Ib3b060c60d6037f664636b8854aa488573826a06
diff --git a/playbooks/zuul-stream/fixtures/test-stream.yaml b/playbooks/zuul-stream/fixtures/test-stream.yaml
index 29bbf47..6a31ff8 100644
--- a/playbooks/zuul-stream/fixtures/test-stream.yaml
+++ b/playbooks/zuul-stream/fixtures/test-stream.yaml
@@ -30,7 +30,7 @@
     - name: Run a shell task with an ansible python exception
       command: echo foo
       args:
-        chdir: /somewhere/that/does/not/exist
+        chdir: /shelltask/somewhere/that/does/not/exist
       failed_when: false
 
     - name: Loop with items on an ansible python exception
@@ -40,5 +40,5 @@
         - item2
         - item3
       args:
-        chdir: /somewhere/that/does/not/exist
+        chdir: /itemloop/somewhere/that/does/not/exist
       failed_when: false