Installed ansible version (for tests) is not compatible with the ansible synthax of the repo

[drosofff]

The
pip install ansible command install ansible 2.7.4, which is not compatible with the syntax of many code lines of the repo.
As a results, the travis tests are failing.
I see 2 options:

pin ansible to pip install ansible==2.4
update the code syntax to be compatible with ansible 2.7.4