python-fitsio: FTBFS on s390x: FAILED fitsio/tests/test_image_compression.py::test_image_compression_gzip_subnormal_cast_to_zero

[Prachi Bhat]

I have raised a PR for this bug which has been merged upstream. 
Here is the bug report :
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1146862&pow_referer=
PR Link:
https://github.com/esheldon/fitsio/pull/531

Regards
Prachi