ApiGateway resources do not match documentation

I don't have time right now to fix it myself, so I'm logging it here.

This is the current code, with in comment what the docs say about required (http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-apigateway-method.html)

```
# Left out all methods that are defined in the right way

class Method(AWSObject):
props = {
"AuthorizationType": (str, False), # Required
"HttpMethod": (str, False), # Required
"ResourceId": (str, False), # Required
"RestApiId": (str, False) # Required

}

class Integration(AWSProperty):
props = {
# missing: "PassthroughBehavior": (str, False),
}

```

Find the Python definitions of Method and Integration shown in the issue, then compare their props entries with the linked AWS CloudFormation API Gateway Method documentation. Confirm which required fields and Integration properties are missing or incorrectly represented, and consider the relevant project tests to verify that the resource definitions match the documentation.

Written by the indexing model from the issue text.