Allow inventory as a directory by using project_dir from Obsah

[ehelms]

No description provided.

[ehelms]

Requires theforeman/obsah#3

The idea is to allow breaking up big package manifests into smaller files inside a directory.

[ekohl]

Would this be clearer?

Suggested change

	inventory = os.path.join(os.getcwd(), 'package_manifest.yaml')
	if os.path.isdir('package_manifests'):
	inventory = os.path.join(os.getcwd(), 'package_manifests')
	return os.environ.get('OBAL_INVENTORY', inventory)
	try:
	return os.environ['OBAL_INVENTORY']
	except KeyError:
	if os.path.isdir('package_manifests'):
	return os.path.join(os.getcwd(), 'package_manifests')
	else:
	return os.path.join(os.getcwd(), 'package_manifest.yaml')

Edit: what always bugged me was package_manifest and packages with tab completion. Should we follow Ansible and use inventory/ or inventory.yaml