AWS::CloudFormation::Delay (new resource)

## 1. Title

#### AWS::CloudFormation::Delay (new resource)

## 2. Scope of request

In order to solve issues such as throttling (#588) or other scenarios where you want to delay the the next resource in line for deployment, I would like to propose to create a new CloudFormation resource type. It should be very similar to `AWS::CloudFormation::WaitCondition`[1], except that we don't need to wait for an external process, only for a period of time.

## 3. Expected behavior

A property should be available to receive the timeout. The value must be in ISO8601 duration format [2], in the form: `PT#H#M#S`, where each # is the number of hours, minutes, and seconds, respectively.

#### In Create/Update/Delete, it should return `SUCCESS` after the amount of time specified by user has passed.

## 4. Suggest specific test cases

This is an example usage for this hypothetical resource type:

```yaml
DomainName1:
Type: AWS::ApiGateway::DomainName
Properties:
DomainName: example.com
CertificateArn: ...

Delay:
Type: AWS::CloudFormation::Delay
Properties:
Timeout: PT1M

# This should only start after 1 minute has passed
DomainName2:
Type: AWS::ApiGateway::DomainName
DependsOn: Delay
Properties:
DomainName: api.example.com
CertificateArn: ...
```

## 5. Helpful Links to speed up research and evaluation

#### [1]: https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-properties-waitcondition.html
#### [2]: http://en.wikipedia.org/wiki/ISO_8601#Durations

## 6. Category

5. Management (CloudTrail, Config...)

Start by reviewing the AWS::CloudFormation::WaitCondition documentation and the ISO 8601 duration reference linked in the issue, then compare the motivation with issue #588. Done means defining the new resource's timeout behavior and ensuring Create, Update, and Delete return SUCCESS only after the requested duration.

Written by the indexing model from the issue text.