routing: Simplify how routes are defined. * No more declaring the type of route parameters -- the sources and generators already know what type each parameter is supposed to be. * Same for variadic parameters -- we know already. * Update cache version to force a clear reload of the config. * Update tests. TODO: simplify code in the `Route` class to use source or generator transparently.

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"