bump version to 3.2.1
bump version to 3.2.1

rootpy/root_numpy,scikit-hep/root_numpy,ndawe/root_numpy,rootpy/root_numpy,ibab/root_numpy,ibab/root_numpy,rootpy/root_numpy,scikit-hep/root_numpy,rootpy/root_numpy,ndawe/root_numpy,ndawe/root_numpy,ndawe/root_numpy,scikit-hep/root_numpy,scikit-hep/root_numpy,ibab/root_numpy,ibab/root_numpy