Verify YAML syntax in gates

Test yaml syntax is correct on new changes.
Fixes current warnings and errors

Change-Id: I5888f8e4a9d27a08506036df2c564b9f2081ccee

.yamllint

@@ -0,0 +1,9 @@
+extends: default
+ignore: |
+  .tox/
+
+rules:
+  line-length: disable
+  truthy: disable
+  braces:
+    max-spaces-inside: 1

.zuul.d/base.yaml

@@ -53,4 +53,3 @@
       - ^doc/.*
     vars:
       publisher: false
-

.zuul.d/centos.yaml

@@ -56,4 +56,3 @@
       publisher: true
     secrets:
       - kolla_dockerhub_creds
-

releasenotes/notes/congress-broken-cbf8ca59d90a85cb.yaml

@@ -1,3 +1,4 @@
+---
 other:
   - Congress doesn't work correctly out of the box and will
-    not deploy.  See Bug #1634641.
+    not deploy. See Bug https://bugs.launchpad.net/kolla-ansible/+bug/1634641.

releasenotes/notes/remove-nova-network-container-69f8c0b61b3aed5a.yaml

@@ -2,4 +2,3 @@
 deprecations:
   - The nova-network service was deprecated, we remove it from
     the nova container.
-

roles/collectd/defaults/main.yml

@@ -1,3 +1,4 @@
+---
 collectd_packages:
   RedHat:
     - collectd

roles/collectd/handlers/main.yml

@@ -1,3 +1,4 @@
+---
 - name: restart collectd service
   service:
     name: collectd

tests/playbooks/post.yml

@@ -1,3 +1,4 @@
+---
 - hosts: all
   roles:
     - collect-collectd

tests/playbooks/pre.yml

@@ -1,3 +1,4 @@
+---
 - hosts: all
   become: true
   roles:

tests/playbooks/run.yml

@@ -1,3 +1,4 @@
+---
 - hosts: all
   vars:
     kolla_inventory_path: "{{ zuul.project.src_dir }}/inventory"

tox.ini

@@ -31,12 +31,16 @@ commands = python setup.py testr --coverage --testr-args='{posargs}'
            coverage report --show-missing
 
 [testenv:pep8]
+deps =
+    {[testenv]deps}
+    yamllint
 commands =
   {toxinidir}/tools/run-bashate.sh
   flake8 {posargs}
   {toxinidir}/tools/validate-all-dockerfiles.sh
   python {toxinidir}/tools/validate-all-file.py
   bandit -r docker kolla tests tools
+  yamllint .
 
 [testenv:bandit]
 commands = bandit -r docker kolla tests tools