[Systemroles] Can we drop the support of Ansible 2.8

[Gris Ge]

Hi,

According to [ansible lifecyle][1], the ansible 2.8 is security fixes
only.

And ansible 2.8 already breaks our CI on Fedora 32 when
trying to collect service facts:

https://github.com/ansible/ansible/issues/69302

Meanwhile, due to lacking of support relative import, the files
in `modules_utils` are required to use:

    from ansible.module_utils.xxx.error import LsrNetworkNmError

Instead of:

    from .error import LsrNetworkNmError

Lacking of relative import also requires a lot hack to our unit tests.

Hence I would like to suggest we drop the support of ansible 2.8.

Any ideas?

[1]:
https://docs.ansible.com/ansible/devel/reference_appendices/release_and_m...
-- 
Gris Ge