Pipe

NEW: One-off pipes, contributed by YoraiLevi:

python
>>> from itertools import combinations

>>> list(range(5) | Pipe(combinations, 2))
[(0, 1), (0, 2), (0, 3), (0, 4), (1, 2), (1, 3), (1, 4), (2, 3), (2, 4), (3, 4)]
>>>

- Dropped [closing pipes](https://github.com/JulienPalard/Pipe/blob/9c4402cdec5b6908a9f7d17dc7ee69b6eeda9a4b/README.md#deprecations-of-pipe-1x=), they were deprecated since 2019-10-22.
- NEW: Pipes are now [partially initializable](https://github.com/JulienPalard/Pipe/blob/9c4402cdec5b6908a9f7d17dc7ee69b6eeda9a4b/README.md#partial-pipes=)