bh_print_sys_params() fails on python

[dmopalmer]

bh_print_sys_params() in bhreader.py calls dict.iteritems() which is no longer in python3.

Since the dict in question is small, there is no reason not to use dict.items() instead.

This is true whether installed with conda -c conda-forge (v0.9) or pip (still v0.8.2 on pypi).

[tritemio]

Thanks for the report. Would you mind sending a PR?

PS: dict.items() in python 3 is a generator like it was dict.iteritems() in python 2, so it is efficient.

[dmopalmer]

The pull request #46 includes other features that it showed were necessary.

[tritemio]

@dmopalmer, thanks for your contribution! It would be nice to also have a test to avoid these errors in the future.

Would you mind adding one to test_bhreader.py?
(the test there use the nose format, but you can use the simpler pytest format as in test_pqreader.py)