Remark: this might be the same issue as: https://github.com/localstack/localstack/issues/1055

There is some kind of error that is occurring when trying to run a lambda function using the invoke command from the javascript SDK. Not sure if I'm doing anything wrong. please advise. This works with a live lambda function.

Call from AWS SDK (Javascript)
```
const { source, identifier } = ctx.params;

const bodyBuffer = await requestToBuffer(ctx.request.req);
const bodyBase64 = bodyBuffer.toString('base64');

const payload = {
        pathParameters: {
            source,
            identifier,
        },
        isBase64Encoded: true,
        body: bodyBase64,
    };
const response = await lambda.invoke({
        FunctionName: 'arn:aws:lambda:us-east-1:000000000000:function:uploadAvatar',
        InvocationType: 'RequestResponse',
        Payload: JSON.stringify(payload),
    }).promise();
```

**Note**: I also tried just using uploadAvatar for the function name.

Error Stack Trace returned by Localstack

```
InternalFailure: Error executing Lambda function: [Errno 7] Argument list too long Traceback (most recent call last):
    File "/opt/code/localstack/localstack/services/awslambda/lambda_api.py", line 301, in run_lambda
      event, context=context, version=version, asynchronous=asynchronous)
    File "/opt/code/localstack/localstack/services/awslambda/lambda_executors.py", line 136, in execute
      result, log_output = self.run_lambda_executor(cmd, environment, asynchronous)
    File "/opt/code/localstack/localstack/services/awslambda/lambda_executors.py", line 58, in run_lambda_executor
      process = run(cmd, asynchronous=True, stderr=subprocess.PIPE, outfile=subprocess.PIPE, env_vars=env_vars)
    File "/opt/code/localstack/localstack/utils/common.py", line 666, in run
      return do_run(cmd)
    File "/opt/code/localstack/localstack/utils/common.py", line 656, in do_run
      stderr=stderr, stdout=stdout_arg, env=env_dict, cwd=cwd)
    File "/opt/code/localstack/.venv/lib/python2.7/site-packages/subprocess32.py", line 825, in __init__
      restore_signals, start_new_session)
    File "/opt/code/localstack/.venv/lib/python2.7/site-packages/subprocess32.py", line 1574, in _execute_child
      raise child_exception_type(errno_num, err_msg)
  OSError: [Errno 7] Argument list too long
```

Localstack configuration environment variables:
```
SERVICES=lambda,sns,s3,ses,cloudformation,cloudwatch,apigateway
DEFAULT_REGION=us-east-1
HOSTNAME=cloud
HOSTNAME_EXTERNAL=cloud.dev.leaguegamer.org
LOCALSTACK_HOSTNAME=cloud
USE_SSL=false
LAMBDA_EXECUTOR=docker
DATA_DIR=/tmp/localstack/data
PORT_WEB_UI=8080
LAMBDA_DOCKER_NETWORK=leaguegamer_default
```

This is running using the `localstack/localstack` docker image
self,
        forward_url: str,
        lambda_function: LambdaFunction,
        event: Union[Dict, bytes],
        context: LambdaContext,
        invocation_type: str,
    ) -> InvocationResult:
        func_name = lambda_function.name()
        url = "%s%s/functions/%s/invocations" % (forward_url, API_PATH_ROOT, func_name)
        copied_env_vars = lambda_function.envvars.copy()
        copied_env_vars["LOCALSTACK_HOSTNAME"] = config.HOSTNAME_EXTERNAL
        copied_env_vars["LOCALSTACK_EDGE_PORT"] = str(config.EDGE_PORT)
        headers = aws_stack.mock_aws_request_headers("lambda")
        headers["X-Amz-Region"] = lambda_function.region()
        headers["X-Amz-Request-Id"] = context.aws_request_id
        headers["X-Amz-Handler"] = lambda_function.handler
        headers["X-Amz-Function-ARN"] = context.invoked_function_arn
        headers["X-Amz-Function-Name"] = context.function_name
        headers["X-Amz-Function-Version"] = context.function_version
        headers["X-Amz-Role"] = lambda_function.role
        headers["X-Amz-Runtime"] = lambda_function.runtime
        headers["X-Amz-Timeout"] = str(lambda_function.timeout)
        headers["X-Amz-Memory-Size"] = str(context.memory_limit_in_mb)
        headers["X-Amz-Log-Group-Name"] = context.log_group_name
        headers["X-Amz-Log-Stream-Name"] = context.log_stream_name
        headers["X-Amz-Env-Vars"] = json.dumps(copied_env_vars)
        headers["X-Amz-Last-Modified"] = str(int(lambda_function.last_modified.timestamp() * 1000))
        headers["X-Amz-Invocation-Type"] = invocation_type
        headers["X-Amz-Log-Type"] = "Tail"
        if context.client_context: