* Lean on API validation for tower_inventory_source arg errors
used for
- validating needed credential is given
- missing source_project for scm sources
* Add warning when config is specified in 2 places
Fix up unit tests, address multiple comments re: backwards compatibility, redundant methods, etc.
Update new_name and variables parameters, update unit tests
Splitting out tower_inventory_source from tower_group
Copy/Paste typo fix and README update for breaking backwards compatability
Update credential_type module and unit tests