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"}
```
try:
        with open(os.devnull, 'w') as devnull:
            subprocess.check_output('docker ps', stderr=devnull, shell=True)
        return True
    except Exception:
        return False
def is_linux():
    try:
        out = subprocess.check_output('uname -a', shell=True)
        out = out.decode('utf-8') if isinstance(out, six.binary_type) else out
        return 'Linux' in out
    except subprocess.CalledProcessError:
        return False
LAMBDA_EXECUTOR = os.environ.get('LAMBDA_EXECUTOR', '').strip()
if not LAMBDA_EXECUTOR:
    LAMBDA_EXECUTOR = 'docker'
    if not has_docker():
        LAMBDA_EXECUTOR = 'local'
LAMBDA_FALLBACK_URL = os.environ.get('LAMBDA_FALLBACK_URL', '').strip()
CONFIG_ENV_VARS = ['SERVICES', 'HOSTNAME', 'HOSTNAME_EXTERNAL', 'LOCALSTACK_HOSTNAME', 'LAMBDA_FALLBACK_URL',
                   'LAMBDA_EXECUTOR', 'LAMBDA_REMOTE_DOCKER', 'LAMBDA_DOCKER_NETWORK', 'USE_SSL', 'DEBUG',
                   'KINESIS_ERROR_PROBABILITY', 'DYNAMODB_ERROR_PROBABILITY', 'PORT_WEB_UI', 'START_WEB',
                   'DOCKER_BRIDGE_IP', 'DEFAULT_REGION', 'LAMBDA_JAVA_OPTS', 'LOCALSTACK_API_KEY',
                   'LAMBDA_CONTAINER_REGISTRY']
for key, value in six.iteritems(DEFAULT_SERVICE_PORTS):
    clean_key = key.upper().replace('-', '_')
    CONFIG_ENV_VARS += [clean_key + '_BACKEND', clean_key + '_PORT', clean_key + '_PORT_EXTERNAL']
CONFIG_ENV_VARS += ['LOCALSTACK_' + v for v in CONFIG_ENV_VARS]
def ping(host):