Adding yamllint configuration file and fixing style violations

Signed-off-by: Jiri Podivin <jpodivin@redhat.com>
Change-Id: I13d8b91c20a08d0b59bd644bd19605311355be05

.yamllint

@@ -0,0 +1,14 @@
+---
+extends: default
+
+rules:
+  line-length:
+    # matches hardcoded 160 value from ansible-lint
+    max: 160
+  indentation:
+    spaces: consistent
+    indent-sequences: true
+    check-multi-line-strings: false
+
+ignore: |
+  releasenotes/notes/*.yaml

.zuul.yaml

@@ -1,3 +1,4 @@
+---
 - job:
     name: validations-libs-functional
     parent: devstack

playbooks/post.yaml

@@ -1,3 +1,4 @@
+---
 - hosts: tempest
   vars:
     tox_envlist: functional

skiplist-example.yaml

@@ -1,3 +1,4 @@
+---
 check-ram:
   hosts: all
   # reason and lp key is not mandatory for the VF. Those values are in the list