Drop internal absolute URI

[Bartvds]

Should be unnecessary but validator doesn't agree? Weird.

[geraintluff]

Is this tv4, or another validator?

If so, I can see how it could give odd behaviour, but it'd be good to handle it better.

[Bartvds]

Of course tv4! 😄

Relevant parts:

Add schema:

https://github.com/Bartvds/package.json-schema/blob/master/test/test.js#L98-L99

Validate, could be a fragment:

https://github.com/Bartvds/package.json-schema/blob/master/test/test.js#L80