Add yamllint and ansible-lint to travis for all roles

[lerwys]

Problem: There are many issues with linter, both yaml and ansible. We should add a target to travis to run these linters for all roles.

[carneirofc]

One thing that is not directly related to this but will certainly mitigate problems with bad code being uploaded is the usage of pre-commit. More specifically if we enable ansible-lint within it, as describe here https://ansible-lint.readthedocs.io/en/latest/configuring.html#pre-commit-setup.
I have been using pre-commit on most of my projects and it has been really helpful.
Every contributor must use pre-commit though (which is not difficult at all).

[carneirofc]

PR #295 will address this problem