Fixed - Invalid `repr` for atomic singleton intervals.
1.5.2
Fixed - Invalid comparisons when both `Interval` and `AtomicInterval` are compared.
1.5.1
Fixed - [1](https://github.com/AlexandreDecan/portion/issues/1) by making empty intervals always resolving to `(P.inf, -P.inf)`.
1.5.0
Added - `Interval.__init__` accepts `Interval` instances in addition to `AtomicInterval` ones.
1.4.0
Added - Function `P.to_string` to export an interval to a string, with many options to customize the representation. - Function `P.from_string` to create an interval from a string, with many options to customize the parsing.