With today's update, API Gateway consistently fails to find any of its' defined paths.

For example, the following `serverless.yml` :
```yaml
service: "localtest"

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

functions:
  hello:
    handler: "handler.hello"
    events:
      - http:
          path: "/"
          method: "get"
          integration: "lambda-proxy"
      - http:
          path: "/test"
          method: "get"
          integration: "lambda-proxy"
plugins:
  - "serverless-localstack"

custom:
  localstack:
    stages:
      - "local"
```

If deployed, will result in the following:
```
~$ sls deploy --stage local
Serverless: Using serverless-localstack
Serverless: Packaging service...
Serverless: Excluding development dependencies...
Serverless: Creating Stack...
Serverless: Checking Stack create progress...
.
Serverless: Stack create finished...
Serverless: Uploading CloudFormation file to S3...
Serverless: Uploading artifacts...
Serverless: Uploading service localtest.zip file to S3 (3.02 KB)...
Serverless: Validating template...
Serverless: Skipping template validation: Unsupported in Localstack
Serverless: Updating Stack...
Serverless: Checking Stack update progress...
.
Serverless: Stack update finished...
Service Information
service: localtest
stage: local
region: us-east-1
stack: localtest-local
resources: 11
api keys:
  None
endpoints:
  GET - http://localhost:4567/restapis/sz3ijrff91/local/_user_request_/
  GET - http://localhost:4567/restapis/sz3ijrff91/local/_user_request_/test
functions:
  hello: localtest-local-hello
layers:
  None
Serverless: Run the "serverless" command to setup monitoring, troubleshooting and testing.
~$ curl http://localhost:4567/restapis/sz3ijrff91/local/_user_request_/
{"message": "Unable to find integration for path /restapis/sz3ijrff91/local/_user_request_/"}
~$ curl http://localhost:4567/restapis/sz3ijrff91/local/_user_request_/test
{"message": "Unable to find integration for path /restapis/sz3ijrff91/local/_user_request_/test"}
```
if method == 'OPTIONS' and 'Origin' in headers:
            
            return get_cors_response(headers)
        return make_error('Unable to find integration for path %s' % path, 404)
    uri = integration.get('uri')
    if method == 'POST' and integration['type'] == 'AWS':
        if uri.endswith('kinesis:action/PutRecords'):
            template = integration['requestTemplates'][APPLICATION_JSON]
            new_request = aws_stack.render_velocity_template(template, data)
            
            headers = aws_stack.mock_aws_request_headers(service='kinesis')
            headers['X-Amz-Target'] = kinesis_listener.ACTION_PUT_RECORDS
            result = common.make_http_request(url=TEST_KINESIS_URL,
                method='POST', data=new_request, headers=headers)
            return result
        elif uri.startswith('arn:aws:apigateway:') and ':sqs:path' in uri:
            template = integration['requestTemplates'][APPLICATION_JSON]
            account_id, queue = uri.split('/')[-2:]
            region_name = uri.split(':')[3]
            new_request = aws_stack.render_velocity_template(template, data) + '&QueueName=%s' % queue
            headers = aws_stack.mock_aws_request_headers(service='sqs', region_name=region_name)
            url = urljoin(TEST_SQS_URL, '%s/%s' % (account_id, queue))
            result = common.make_http_request(url, method='POST', headers=headers, data=new_request)
            return result
        else:
            msg = 'API Gateway action uri "%s" not yet implemented' % uri
            LOGGER.warning(msg)
            return make_error(msg, 404)
    elif integration['type'] == 'AWS_PROXY':
        if uri.startswith('arn:aws:apigateway:') and ':lambda:path' in uri: