Issue with reading FUGA 2.9 look-up tables

Issue reported by david.bieniek@innogy.com:

zeta0 = struct.unpack('d', fid.read(8))[0] throws the error “struct.error: unpack requires a buffer of 8 bytes” when parsing FUGA look-up tables created with FUGA 2.9. I confirm that commenting that line and manually setting the value of zeta0 to something else, solves the issue. Please let us know if there’s a simple way to fix this. We would also like to know if there is a specific Fuga version that should be used to create LUTs used with PyWake.

David: please provide us with some look-up tables that are failing, so that we can reproduce this problem.