Assure standalone jobs are run when requirements are updated

Removes: requirements.txt, setup.cfg and setup.py files from the
irrelevant list because any change made to this files can affect
the functionality of the product in a critical way.

This makes the need to create extra empty changeset for testing
changes made to these files.

Change-Id: I637b3da0a4beacadc63846eb4cd08d510bafd4ac

zuul.d/standalone-jobs.yaml

@@ -10,6 +10,18 @@
     branches: ^(?!stable/(newton|ocata|pike|queens)).*$
     vars:
       featureset: '052'
+    irrelevant-files:
+      - ^.*\.md$
+      - ^.*\.rst$
+      - ^doc/.*$
+      - ^etc/.*$
+      - ^metadata.json$
+      - ^releasenotes/.*$
+      - ^test-requirements.txt$
+      - ^spec/.*$
+      - ^Puppetfile.*$
+      - tox.ini
+      # like parent but with requirements.txt and setup.py removed
 
 - job:
     name: tripleo-ci-fedora-28-standalone
@@ -22,3 +34,15 @@
       featureset: '052'
       featureset_override:
         run_tempest: false
+    irrelevant-files:
+      - ^.*\.md$
+      - ^.*\.rst$
+      - ^doc/.*$
+      - ^etc/.*$
+      - ^metadata.json$
+      - ^releasenotes/.*$
+      - ^test-requirements.txt$
+      - ^spec/.*$
+      - ^Puppetfile.*$
+      - tox.ini
+      # like parent but with requirements.txt and setup.py removed