Fix node 10 compilation error

[alexdima]

This fixes #52 and allows for the project to be compiled with node 10.

I've used the pattern presented in https://nodejs.org/api/addons.html#addons_wrapping_c_objects i.e.

void MyObject::New(const FunctionCallbackInfo<Value>& args) {
  Isolate* isolate = args.GetIsolate();

  if (args.IsConstructCall()) {
    // Invoked as constructor: `new MyObject(...)`
    double value = args[0]->IsUndefined() ? 0 : args[0]->NumberValue();
    MyObject* obj = new MyObject(value);
    obj->Wrap(args.This());
    args.GetReturnValue().Set(args.This());
  } else {
    // Invoked as plain function `MyObject(...)`, turn into construct call.
    const int argc = 1;
    Local<Value> argv[argc] = { args[0] };
    Local<Context> context = isolate->GetCurrentContext();
    Local<Function> cons = Local<Function>::New(isolate, constructor);
    Local<Object> result =
        cons->NewInstance(context, argc, argv).ToLocalChecked();
    args.GetReturnValue().Set(result);
  }
}

[alexdima]

The build has failed, but I think that is unrelated to my changes. Perhaps a flaky test?

[implausible]

Thank you so much for the help. I'm sorry I couldn't get to you sooner.

[jagu-sayan]

@implausible Can you publish a new github release and npm release with all this fixes ?

I do npm install @atom/nsfw for now with node 10

[implausible]

@jagu-sayan Thank you for the reminder. I've made a 1.1.0 release.

https://github.com/Axosoft/nsfw/releases/tag/v1.1.0