Add YAMLLint for static check

Add YAMLLint for static check

JIRA: OCTO-160

1)Install yamllint first in case pod didn't install. If installed, it would
info "already satisfied".

2)delete virtualenv of releng_yamllint.

Current CI commit gate is simple, just have flake8 check in part of projects,
it's better to apply more check tools to more projects.
Yaml files could be checked by YAMLLint when the project is configed in releng.
YAMLLint does not only check for syntax validity, but for weirdnesses like key
repetition and cosmetic problems such as lines length, trailing spaces, indentation,
etc.

Change-Id: I8591385ed32942e0af7f7afdde435313af5707e5
Signed-off-by: KingPoo <haojingbo@huawei.com>