PR: Include "micro" in the update_type

[mrclary]

fixes: Update info doesn't contain the required fields to perform the update. Aborting!

'micro' is not one of ['minor', 'major']

Failed validating 'enum' in schema['properties']['update_type']:
    {'type': 'string',
     'default': 'minor',
     'enum': ['minor', 'major'],
     'description': 'Type of update to be performed.'}

On instance['update_type']:
    'micro'