hadley/testthat — pull request #123 by krlmlr (2014-02-06 14:31:58+00:00)
Title: Depend on methods package again

Partial revert of 68c0a2ce8e9bd0. The @importFrom needs to stay in place to
calm R CMD check.

Fixes #122. More work needs to be done if we also want to support

```
Rscript -e "testthat::test_package('testthat')"
```