Nesting tests incorrect

[blakef]

Nesting isn't working, tests don't cover correctly. This is the expected behaviour:

Examples:

let a = new JSONifier({namespace: 'a'}).add({1:2});
> a.build({nest: true}).next().value
{'a': {'1': '2'}}
> a.build({nest: false}).next().value
{'1': '2'}
> a.build('a').next().value
{'1': '2'}
> a.build().next().value
{'a': {'1': '2'}}

Used with namespaces

> a.build({namespace: 'a', nest: true}).next().value
{'1': '2'}
> a.build({namespace: 'a', nest: true}).next().value
{'a': {'1': '2'}}

This is useful because it allows us to use namespaces as a filter (see #4).

TODO:

Add test which represent these use cases.