Changed success code + Fix for nested resource + Unit tests

[mblarsen]

Changed the default behaviour off successful request for CREATE and DELETE to respond with 201 and 204 respectfully.

[mblarsen]

I've added a simple test suite, because I had some problems with naming nested resources, when there is more than one.

The last test, which is the nested with renamed resources, fails. Perhaps I'm doing it all wrong.

      rest.resource('users');
      rest.resource('users', 'projects', { projects_resource: 'books' });
      rest.resource('users', 'projects', 'todos', { projects_resource: 'books', todos_resource: 'tasks' });

[mblarsen]

Latest commit has a fix to lib/api.js with regards to nested resources with alternate names, thus the test suites is all green :)