Added hdf5 data file for Interferometry notebooks

Added hdf5 data file for notebooks 2_Interferometry.ipynb
and 2_Interferometry_Solution.ipynb
Edits to Interferometry tutorials to unzip data file

Edits to notebooks 2_Interferometry.ipynb and
2_Interferometry_Solution.ipynb to unzip data file
kat4_int_example_github.hdf5.bz2