If a line match is found in the file and no regexp is specified, insertbefore would improperly try to add a line if set to BOF.
Add tests for this scenario.
* Insert lines before or after when the regexp exists elsewhere in the file
* Correct filter syntax in lineinfile integration test
* Use multi-line YAML syntax on lineinfile tests
Unify indentation
* Add lineinfile tests for same line matched to different regexps
* Remove debug statement from test
