Adding yamllinter to ci steps (#1556)

* Adding yaml linter to ci check

* Minor linting fixes from yamllint

* Changing CI to install python pkgs from requirements.txt

- adding in a secondary requirements.txt for tests
- moving yamllint to tests requirements

roles/dnsmasq/defaults/main.yml

@@ -4,12 +4,12 @@
 
 # Max of 4 names is allowed and no more than 256 - 17 chars total
 # (a 2 is reserved for the 'default.svc.' and'svc.')
-#searchdomains:
-#  - foo.bar.lc
+# searchdomains:
+#   - foo.bar.lc
 
 # Max of 2 is allowed here (a 1 is reserved for the dns_server)
-#nameservers:
-#  - 127.0.0.1
+# nameservers:
+#   - 127.0.0.1
 
 dns_forward_max: 150
 cache_size: 1000