Tags attached to an IAM user are not saved. Create a user with attached tags. The response from the create user doesn't include the tags and when you run a GetUser the tags are not included.
```
aws-sdk-swift % aws --endpoint-url http://localhost:4593 iam create-user --user-name test-user --tags Key=test,Value=hello
```
produces output
```
{
    "User": {
        "Path": "/",
        "UserName": "test-user",
        "UserId": "peldynzrvm2tofi6nmmr",
        "Arn": "arn:aws:iam::000000000000:user/test-user",
        "CreateDate": "2019-10-23T08:46:31.305Z"
    }
}
```
The GetUser call produces exactly the same output
```
aws --endpoint-url http://localhost:4593 iam get-user --user-name test-user
```


I am running localstack as follows
```
docker run -d -p 4593:4593 -e SERVICES='iam' localstack/localstack
```
from moto.iam.responses import IamResponse, GENERIC_EMPTY_TEMPLATE
from moto.iam.models import iam_backend as moto_iam_backend
from localstack import config
from localstack.constants import DEFAULT_PORT_IAM_BACKEND
from localstack.services.infra import start_moto_server
def patch_moto():
    def delete_policy(self):
        policy_arn = self._get_param('PolicyArn')
        moto_iam_backend.managed_policies.pop(policy_arn, None)
        template = self.response_template(GENERIC_EMPTY_TEMPLATE)
        return template.render(name='DeletePolicyResponse')
    if not hasattr(IamResponse, 'delete_policy'):
        IamResponse.delete_policy = delete_policy
def start_iam(port=None, asynchronous=False, update_listener=None):
    port = port or config.PORT_IAM
    patch_moto()
    return start_moto_server('iam', port, name='IAM', asynchronous=asynchronous,
        backend_port=DEFAULT_PORT_IAM_BACKEND, update_listener=update_listener)