tests: add simple test cases for line iterators
tests: add simple test cases for line iterators

We'll test them some more though after new functionalities in
gpio-mockup are released in kernel 4.11.

Signed-off-by: Bartosz Golaszewski <108de5fbc428215dc26df4468b48691526611148@gmail.com>

brgl/libgpiod,brgl/libgpiod,brgl/libgpiod,brgl/libgpiod