Minor bug regarding image.name vs image.repository structure in values.yaml

[consideRatio]

It seems to me that we have some invalid logic regarding use of name or repository as a key when updating values.yaml files with image tags.

chartpress/chartpress.py

Lines 27 to 28 in c1133e1

	# name of possible repository keys used in image value
	IMAGE_REPOSITORY_KEYS = {'name', 'repository'}

chartpress/chartpress.py

Lines 536 to 538 in c1133e1

	for path_key, path_value in modifications.items():
	if not isinstance(path_value, dict) or set(path_value.keys()) != {'repository', 'tag'}:
	raise ValueError(f"I only understand image updates with 'repository', 'tag', not: {path_value!r}")