* Add Bitbucket pipelines variable module
* Add tests
* Remove parameters check for `absent` state
* Update version_added documentation field
* Minor fixes
* A few additional cosmetic changes
* Move to source_control
* Rename lib/ansible/modules/source_control/bitbucket_pipelines_variable.py to lib/ansible/modules/source_control/bitbucket/bitbucket_pipelines_variable.py
* Reflect directory change
* Move these imports as well
* Rename 'key' parameter (API) to 'name' (GUI)
* Add missing __init__.py files to mark modules
* Rename module (pipeline should be singular)
* Adjust module references and variable names after renaming
