- update to 1.0.1:
* Fix calls to opaque objects and use provider interface calls
instead. `#126
* Implement backjumping to significantly speed up the
resolution process by skipping over irrelevant parts of the
resolution search space. `#113
* A new reporter hook ``rejecting_candidate`` is added,
replacing ``backtracking``.
* The hook is called every time the resolver rejects a
conflicting candidate before trying out the next one in line.
* Some valid states that were previously rejected are now
accepted. This affects states where multiple candidates for
the same dependency conflict with each other.
The ``information`` argument passed to
``AbstractProvider.get_preference`` may now contain empty
iterators. This has always been allowed by the method
definition but it was previously not possible in practice.

* edges that lead to the detected conflicts.
* Provide type stubs for most classes.