Save output dataframe as HDF5, not Pickle
Created by: julianhess
I was having issues with reading Pickles from a buffer — as updated in ee641937, in order to accommodate multiple backends, the output Pickle is now read via a transport, rather than with a simple pd.read_pickle("filename")
call.
HDF5 is more amenable to being read/written via buffers, so I've switched over.