Bugfix/undefined returned by some api methods

[GearoidSugrue]

Hello! Firstly thanks for this node module, its great! Especially all the Types and Interfaces, it saved me a lot of time :)
I've found a few small issues and would like to help fix.

The first one is that NS v3 responses are different from the v2 ones. They don't follow the same response pattern of:

{	
   links: ...
   meta: ...
   payload: ...
   etc...
}

Instead, they just return the data. For example, GET /trips response is:

{
  "trips": [
      ....
   ]
}

It's an simple fix. Just resolve(message) instead of resolve(message.payload) in getTrip and getTrips in api.ts.

Most of the other changes were to fix the Typescript errors it caused. I hope my solution is ok? Feel free to make recommendations!
Also, I had to upgrade typescript. It was failing to build because of the comments in the tsconfig.json file.

As I mentioned, there are a few other minor issues. I'll create separate issues for them.

[MichielMag]

Thanks for the PR! I'll check it and functionally test it soon.

[GearoidSugrue]

Hey, have you had a chance to look at this? 😄