doctest runner for Node (also fix name and version)
fix `require` inside evaller-run script under Node

`require` works correctly when it goes together with `module` object.
So we run expression with:

    vm.runInContext(expression, {require: require, module: module});

But that's not all. We also:

1. fix relative lookups by setting `module.filename` to script path;
2. keep state between tests by passing context around manually.
Merge pull request #44 from shamrin/node-runner

Node test runner