Add in the ability to add tags for a dataset

[mbforr]

adding in the ability in the api to add a dataset tag. it would be nice to do it on upload and manually for different tables in the account.

demo code is attached! thanks @oleurud

from carto.datasets import DatasetManager

ds_manager = DatasetManager(auth_client)

table_metadata = ds_manager.get(TABLE)
table_metadata.tags = ['test3']
table_metadata.save()

[Jesus89]

https://app.clubhouse.io/cartoteam/story/93718/add-remove-tags-for-a-datasets