When trying to deploy a serverless service that does not currently deploy correctly onto localstack using a custom deployment bucket, the lambdas seems to be created regardless (???) but not as part of the stack, with localstack outputting `botocore.errorfactory.ResourceConflictException: An error occurred (ResourceConflictException) when calling the CreateFunction operation: Function already exist` .

For example, the `serverless.yml` below would currently fail to deploy due to  #1676 , but because a `deploymentBucket` was added, it will instead fail due to `Function already exist`. Subsequently removing `deploymentBucket` or even `events` from the the file will not allow it to deploy - it will fail until localstack is restarted ( or until the lambda is manually deleted?).

I've also reproduced this with services suffering from #1675. 

```yaml
service: "localtest"

provider:
  name: "aws"
  runtime: "nodejs10.x"
  deploymentBucket:
    name: "testbucket"

functions:
  hello:
    handler: "handler.hello"
    events:
      - schedule: "cron(0 * * * ? *)"

plugins:
- "serverless-localstack"

custom:
  localstack:
    stages:
      - "local"
```
""" Update and fix the ID(s) of the given resource. """
        
        
        
        
        
        
        
        
        
        
        backend = apigw_models.apigateway_backends[region_name]
        if isinstance(resource, apigw_models.RestAPI):
            backend.apis.pop(resource.id, None)
            backend.apis[new_id] = resource
            
            
            client = aws_stack.connect_to_service('apigateway')
            resources = client.get_resources(restApiId=new_id, limit=500)['items']
            
            assert len(resource.resources) == 1
            resource.resources = {}
            for res in resources:
                res_path_part = res.get('pathPart') or res.get('path')
                child = resource.add_child(res_path_part, res.get('parentId'))
                resource.resources.pop(child.id)
                child.id = res['id']
                child.api_id = new_id
                resource.resources[child.id] = child
            resource.id = new_id