Testthat: Reconsider directory layout

[hadley]

(i.e. the working directory needs to be the project root)

This needs to be a long term plan, but would make testthat more consistent with other packages. Would need to start by emitting warnings so that R CMD check doesn't fail, but you're encouraged to update your tests.

[hadley]

It might be possible to do this as part of a bigger behaviour switch:

• Put tests directly in tests/
• Eliminate use of context()
• Don't use reporters for R CMD check
• Eliminate bare expectations

[krlmlr]

I like the idea of putting tests under tests, but why do we need to eliminate bare expectations?

[hadley]

Just because it adds a bunch of extra code and I’d rather push people towards one consistent style. I might be wrong.

[hadley]

context() is no longer necessary as of 2.1.0

[hadley]

Superseded by #1027