<!--- Verify first that your feature was not already discussed on GitHub -->
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##### SUMMARY
elb_network_lb and elb_target_group should support UDP, currently only HTTP, HTTPS and TCP are supported by ansible.

Based on the current pages, UDP and TCP_UDP are supported as protocols:
- https://docs.aws.amazon.com/elasticloadbalancing/latest/network/create-listener.html
- https://docs.aws.amazon.com/elasticloadbalancing/latest/network/create-target-group.html

##### ISSUE TYPE
- Feature Idea

##### COMPONENT NAME
- elb_target_group
- elb_network_lb

##### ADDITIONAL INFORMATION
It would be useful to use UDP as a protocol for an NLB, additionally, attached target groups would need to support UDP.

TCP_UDP is another protocol that it would be useful to add support for (a port that would take TCP or UDP traffic and not care)

<!--- Paste example playbooks or commands between quotes below -->
```yaml
    - name: Create logstash target group
      elb_target_group:
        name: logstash_bunyan_production_tg
        protocol: udp
        port: 5600
        vpc_id: "{{ vpc_facts.vpcs[0].id }}"
        state: present

    - name: Create nlb
      elb_network_lb:
        name: logstash_nlb
        subnets: "{{ private_subnets + public_subnets }}"
        health_check_path: "/"
        health_check_port: "9600"
        health_check_protocol: "http"
        protocol: "udp"
        port: "5600"
        listeners:
          - Protocol: UDP
            Port: 5600
            DefaultActions:
              - Type: forward
                TargetGroupName: logstash_bunyan_production_tg
        state: present
```

<!--- HINT: You can also paste gist.github.com links for larger files -->

type: str
    sample: mytargetgroup
unhealthy_threshold_count:
    description: The number of consecutive health check failures required before considering the target unhealthy.
    returned: when state present
    type: int
    sample: 2
vpc_id:
    description: The ID of the VPC for the targets.
    returned: when state present
    type: str
    sample: vpc-0123456
'''
import time
try:
    import botocore
except ImportError:
    pass  
from ansible.module_utils.aws.core import AnsibleAWSModule
from ansible.module_utils.ec2 import (camel_dict_to_snake_dict, boto3_tag_list_to_ansible_dict, ec2_argument_spec,
                                      compare_aws_tags, ansible_dict_to_boto3_tag_list)
from distutils.version import LooseVersion
def get_tg_attributes(connection, module, tg_arn):
    try:
        tg_attributes = boto3_tag_list_to_ansible_dict(connection.describe_target_group_attributes(TargetGroupArn=tg_arn)['Attributes'])
    except (botocore.exceptions.ClientError, botocore.exceptions.BotoCoreError) as e:
        module.fail_json_aws(e, msg="Couldn't get target group attributes")
    
    return dict((k.replace('.', '_'), v) for k, v in tg_attributes.items())
def get_target_group_tags(connection, module, target_group_arn):