1.0.0 - `@cases_fixture` + pytest 2.x support

Pytest 2.x is now supported. Fixes #14

New feature: @cases_fixture ! Now you can put your cases data retrieval in a fixture so that its duration does not enter into the test duration. This is particularly interesting if you use pytest-harvest to create benchmarks: you probably do not want the case data retrieval/parsing to be counted in the test duration, especially if you use caching on the case function to accelerate subsequent retrievals. Fixes #15

See documentation for details.