Clean up bad layout files in zuul tests

Clean up the bad layout files in the zuul tests by removing a redundant
file (bad_pipeline and bad_pipeline1.yaml were identical). Annotate the
reason the layout is bad in each file. Finally remove a redundant swift
section. Both bad switf sections were failing for the same reason, a
missing name entry.

Change-Id: I0fd09da1fb0ec7443fa7d12a3b31809546a01afd
diff --git a/tests/fixtures/layouts/bad_pipelines10.yaml b/tests/fixtures/layouts/bad_pipelines10.yaml
index 5248c17..ddde946 100644
--- a/tests/fixtures/layouts/bad_pipelines10.yaml
+++ b/tests/fixtures/layouts/bad_pipelines10.yaml
@@ -4,4 +4,5 @@
 
 projects:
   - name: foo
-    merge-mode: foo
\ No newline at end of file
+    # merge-mode must be one of merge, merge-resolve, cherry-pick.
+    merge-mode: foo