[fix] Fixes #16

Pass `urls` to initial call to `this.nextPublicNpm()`
Merge pull request #17 from evanlucas/bug/urls

[fix] Fixes #16
[dist] Version bump. 1.3.4
[feature] Add tests (per #14)

- Added tests for both the server and proxy logic
- Added script for generating code coverage
- Added mocha@1.18.2 as a dev dependency