v2.0.1
------
    Fixing an issue with lmfit backend, which makes use of the inverse errors
    and not the errors as previously passed by nPDyn.

v2.0
----
    The version introduces the builtin Model interface feature as well
    as the interface with the lmfit package as backend for data fitting.

    In addition, data structure was changed as compared to v1.0 and
    simplified. There is only a 'QENSType' and 'FWSType' now, for which
    the 'data' attribute contains new entries.

    For both 'QENSType' and 'FWSType', the intensities and errors are 3D
    numpy arrays where the first axis correspond to the observable, the
    second to the momentum transfer q-values and the last to the energies.

    For the package structure itself, most of the files were moved to the root
    and the actual nPDyn code is in the 'nPDyn' directory in root.

    It includes new tests and more extensive documentation.

v1.0
----
    Initial version of nPDyn.
    We keep track of it as it has been used for some publications.
