Hey, first thanks for this amazing project!

I was trying to use serverless and localstack together, and I was having problems deploying a lambda function. In the logs I was getting errors 502 all the time:

```Serverless: Recoverable error occurred (502), sleeping for 5 seconds. Try 4 of 4

  Serverless Error ---------------------------------------

  502
```

I then start tracking the error, since this one above didn't give me much information, and I ended up at Serverless calling cloud formation's `describe-stack-events` using the unique stack id, instead of the stack name:

https://github.com/serverless/serverless/blob/f93b27bf684d9a14b1e67ec554a7719ca3628135/lib/plugins/aws/lib/monitorStack.js#L33

That is a legit request, as seen in the aws docs:

https://docs.aws.amazon.com/cli/latest/reference/cloudformation/describe-stack-events.html#options

The cloudformation mock within localstack accepts the stackName without problems:

```
> aws --endpoint-url=http://localhost:4581 cloudformation list-stacks    
{
    "StackSummaries": [
        {
            "StackId": "arn:aws:cloudformation:us-east-1:000000000000:stack/steamRoller-local/fcbeb0ef-9739-44a2-8a37-f599bbf4e5f3",
            "StackName": "steamRoller-local",
            "CreationTime": "2011-05-23T15:47:44Z",
            "StackStatus": "UPDATE_COMPLETE",
            "TemplateDescription": "The AWS CloudFormation template for this Serverless application"
        }
    ]
}

> aws --endpoint-url=http://localhost:4581 cloudformation describe-stack-events --stack-name steamRoller-local
{
    "StackEvents": [
        {
            "StackId": "arn:aws:cloudformation:us-east-1:000000000000:stack/steamRoller-local/fcbeb0ef-9739-44a2-8a37-f599bbf4e5f3",
            "EventId": "a49fd67b-ce7b-4a33-9a00-6ebe2242adae",
            "ResourceStatus": "UPDATE_COMPLETE",
            "ResourceType": "AWS::CloudFormation::Stack",
            "Timestamp": "2019-08-10T13:44:44.550022Z",
            "StackName": "steamRoller-local",
            "PhysicalResourceId": "arn:aws:cloudformation:us-east-1:000000000000:stack/steamRoller-local/fcbeb0ef-9739-44a2-8a37-f599bbf4e5f3",
            "StackName": "steamRoller-local",
            "PhysicalResourceId": "arn:aws:cloudformation:us-east-1:000000000000:stack/steamRoller-local/fcbeb0ef-9739-44a2-8a37-f599bbf4e5f3",
            "LogicalResourceId": "steamRoller-local"
        },
        {
            "StackId": "arn:aws:cloudformation:us-east-1:000000000000:stack/steamRoller-local/fcbeb0ef-9739-44a2-8a37-f599bbf4e5f3",
            "EventId": "35ef5c91-99a0-483d-b6b7-e01ee3dda2dd",
            "ResourceStatus": "CREATE_IN_PROGRESS",
            "ResourceType": "AWS::CloudFormation::Stack",
            "Timestamp": "2019-08-10T13:37:51.124574Z",
            "ResourceStatusReason": "User Initiated",
            "StackName": "steamRoller-local",
            "PhysicalResourceId": "arn:aws:cloudformation:us-east-1:000000000000:stack/steamRoller-local/fcbeb0ef-9739-44a2-8a37-f599bbf4e5f3",
            "LogicalResourceId": "steamRoller-local"
        }
    ]
}
```

But it doesn't accept the stackId as the argument (the one used by serverless):

```
> aws --endpoint-url=http://localhost:4581 cloudformation describe-stack-events --stack-name arn:aws:cloudformation:us-east-1:000000000000:stack/steamRoller-local/fcbeb0ef-9739-44a2-8a37-f599bbf4e5f3

An error occurred (502) when calling the DescribeStackEvents operation (reached max retries: 4): Bad Gateway
```

If I have a look at the docker logs I can see:

```
"invalid XML received:\n%s" % (e, xml_string)) botocore.parsers.ResponseParserError: Unable to parse response (syntax error: line 1, column 54), invalid XML received:

b'<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">\n<title>500 Internal Server Error</title>\n<h1>Internal Server Error</h1>\n<p>The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there is an error in the application.</p>\n'
```

That matches what other colleagues were seeing: https://github.com/localstack/localstack/issues/965

Please, make localstack's cloudformation handle the stackId in describe-stack-events and other actions that accepts it. This is a blocker for using localstack for me :/

Thanks
'Subject': subject,
                    'Message': message,
                    'Timestamp': timestamp(format=TIMESTAMP_FORMAT_MILLIS),
                    'MessageAttributes': message_attributes
                }
            }]
        }
        return run_lambda(event=event, context={}, func_arn=func_arn, asynchronous=True)
    except Exception as e:
        LOG.warning('Unable to run Lambda function on SNS message: %s %s' % (e, traceback.format_exc()))
def process_kinesis_records(records, stream_name):
    
    try:
        stream_arn = aws_stack.kinesis_stream_arn(stream_name)
        sources = get_event_sources(source_arn=stream_arn)
        for source in sources:
            arn = source['FunctionArn']
            event = {
                'Records': []
            }
            for rec in records:
                event['Records'].append({
                    'eventID': 'shardId-000000000000:{0}'.format(rec['sequenceNumber']),
                    'eventSourceARN': stream_arn,
                    'kinesis': rec
                })
            run_lambda(event=event, context={}, func_arn=arn)
    except Exception as e:
        LOG.warning('Unable to run Lambda function on Kinesis records: %s %s' % (e, traceback.format_exc()))
def process_sqs_message(message_body, message_attributes, queue_name, region_name=None):