data: Add access to route metadata in the templating data. It's available under `route`. Also, rename `slug` to `rel_url`, because it's confusing when `slug` could be the route metadata of the same name as provided by the default page source. The old `slug` is still there for backwards compatibility though.

sudo: false
language: python
python:
  - "3.4"
  - "3.5"
install:
  - "python setup.py version -f 2.0"
  - "python setup.py sdist --formats=zip"
  - "pip install dist/PieCrust-2.0.zip"
script:
  - "py.test"