'Create a new AWS Secret Access Key and corresponding AWS Access Key ID
for the specified user.  The default status for new keys is Active
If the user_name is not specified, the user_name is determined
implicitly based on the AWS Access Key ID used to sign the request.
:type user_name: string
:param user_name: The username of the user'

def create_access_key(self, user_name=None):

    params = {'UserName': user_name}
    return self.get_response('CreateAccessKey', params)
