[Ifeffit] Larch 0.9.56

Hi Folks, Larch version 0.9.56 is now available on PyPI ( https://pypi.org/project/xraylarch) and should now be installed by default using most installation mechanisms. This really represents a collection of small improvements and bug fixes but includes one emergency bug fix that many people have seen with the latest version of `lmfit` (which was released recently). I believe that this will now work, but please let me know if you continue to have installation problems. Cheers, --Matt Newville