fix : flow plot bug on axis range for histplot and hist2dplot

[Ming-Yan]

change the axis range to fix the bug #431

[andrzejnovak]

Thanks for the super quick fix. Should this affect the existing baseline images? Also could you add a quick test, based on the example in the issue? Perhaps using sth like @check_figures_equal instead of generating a new baseline image test like here:

mplhep/tests/test_inputs.py

Line 56 in bd90705

@check_figures_equal()

[Ming-Yan]

Indeed the split of the broken axis ticks slightly change in this PR. Regarding to the new test based on this issue, I am a bit confused what to compared in this test

[andrzejnovak]

It could either be a simple test just checking if it executes correctly or with the check equal it could be comparing a hist 1 bin histogram to manually plotting histplot([1])

[Ming-Yan]

Indeed I find out the plot could be very different due to the numpy hist not able to have flow bins. create new test with this issue