* add unit test: nested dynamic includes
* nested dynamic includes: avoid AnsibleFileNotFound error
Error was:
Unable to retrieve file contents
Could not find or access 'include2.yml'
Before 8f758204cf, at the end of
'path_dwim_relative' method, the 'search' variable contained amongst
others paths:
'/tmp/roles/testrole/tasks/tasks/included.yml' and
'/tmp/roles/testrole/tasks/included.yml'.
The commit mentioned before removed the last one despite the method
docstrings specify 'with or without explicitly named dirname subdirs'.
* add integration test: nested includes
This change corrects problems reported by the `yamllint` linter.
Since key duplication problems were removed in 4d48711, this commit
mainly fixes trailing spaces and extra empty lines at beginning/end of
files.
