[ENH] Improve AWS resource tagging and allow user to provide custom tags

[richford]

Resolves #248

[arokem]

This is a whacky format. Is there a good reason this is not: {key_val: value_val}?

[richford]

I agree that it's weird. Blame it on AWS and boto3:

• https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-resource-tags.html
• https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/ecr.html#ECR.Client.tag_resource

They expect a list of dictionaries of the form

{"Key": key_val, "Value": value_val}

I wanted to keep both options for parameter input validation so that weirdos who know the AWS format can supply it. And normal folks can also supply a regular python dictionary.

But if this is too ugly for you to bear, we can require the regular python dictionary and then convert it behind the scenes.

[arokem]

No. I suspected this is an AWS weirdness. So long as we support a normal API for normal people...

[arokem]

Looks good to me! Is it ready to merge?

[richford]

Yep! 🚀