Add quick CPT registration method
Remove nonexistent variable refs in args
Fix docblock and remove return
Add function for quick taxonomy registration
Merge branch 'feature/cpt-utilities' into development

* feature/cpt-utilities:
  Add function for quick taxonomy registration
  Fix docblock and remove return
  Remove nonexistent variable refs in args
  Add quick CPT registration method
Bump for minor release v0.5.0
Merge branch 'release/v0.4.0' into development

* release/v0.4.0:
  Bump for minor release v0.5.0