Fix exclude_paths from get_playbooks_and_roles

[ssbarnea]

Fix bug which made impossible to use relative exclude paths as
these where resolved while the file tested where not.

[cans]

Why do you keep making competing changes ?
Similar changes were made in #749. Also your changes won't help with issue #744.
Should I close #749 ? Closed already, had not seen.

[ssbarnea]

@cans That mention PR is huge and contains lots of unrelated changes. A PR should be kept atomic, addressing one issue, so it can easily be reviewed, merged and eventually identified if a regression occurs.

Also the code complexity is unrelated to this bug and should be addressed separately.

[webknjaz]

@cans I'll be glad to review the rest of the changes when submitted separately. It so happened that another PR fixed the issue and was easier to review and accept (because unrelated changes often have problems that block the whole PR even if the related changes are fine because it's hard to identify which part of the change is acceptable to merge already).

@ssbarnea I'd like to encourage you to let PR authors complete their changes if they are not urgent and received updates during the last two weeks. This way we can focus on non-conflicting changes and work in more improvement directions w/o dismissing the hard work that other folks try to contribute.