* Fix test-module failing to validate args
The test-module pass a wrong argument _ansible_tmp cause the validation failed.
Change the argument _ansible_tmp to _ansible_tmpdir to fix this.
* Add a integration test for test-module.
Prior to this change, we don't have a test for test-module.
This change ensure the correctness of test-module script.
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.
