data: Add a top level wrapper for `Linker`. The `family` object is special in that it's "attached" to the current page, so make an object dedicated to that. It removes special code in `Linker`, and makes it possible to go `family.children` directly to get a page's children (i.e. pages in a directory of the same name).

language: python
python:
  - "3.4"
install: "pip install -r requirements.txt"
script: py.test