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"
```
port = port or config.PORT_CLOUDFORMATION
    backend_port = DEFAULT_PORT_CLOUDFORMATION_BACKEND
    print('Starting mock CloudFormation (%s port %s)...' % (get_service_protocol(), port))
    start_proxy_for_service('cloudformation', port, backend_port, update_listener)
    if RUN_SERVER_IN_PROCESS:
        cmd = 'python "%s" cloudformation -p %s -H 0.0.0.0' % (__file__, backend_port)
        env_vars = {'PYTHONPATH': ':'.join(sys.path)}
        return do_run(cmd, asynchronous, env_vars=env_vars)
    else:
        argv = ['cloudformation', '-p', str(backend_port), '-H', '0.0.0.0']
        thread = FuncThread(start_up, argv)
        thread.start()
        return thread
def set_moto_account_ids(resource_json):
    def fix_ids(obj, **kwargs):
        if isinstance(obj, dict):
            for key, value in obj.items():
                if 'arn' in key.lower() and isinstance(value, six.string_types):
                    obj[key] = value.replace(TEST_AWS_ACCOUNT_ID, MOTO_ACCOUNT_ID)
        return obj
    return recurse_object(resource_json, fix_ids)
def get_entity_id(entity, resource_json=None):