Autoflip spectra when f-engine is high band
Add noise demodulated data to hdf5 file

1. Chang corr_grab_h5 to get noise demodulated data from redis
and save in hdf5 data files.

2. Add a section in the config file to map AMI antenna numbers
(currently we're using 3 and 7) to hdf5 data array indices.
This probably should be better thought through, but works for now