update tutorial to use the recommended flopy result reader

[jkall]

The steady state tutorial script shows how to read simulation results by using ModflowHdsRead, line 213-215:

-- Read results

mread_heads = ModflowHdsRead(ml,compiler='l')
t, h, m = mread_heads.read_all(name+'.hds')

But flopy reports this method is deprecated and recommends using "HeadFile".

BTW, I do not really understand why swapaxes (line 218-219) is used in the tutorial. I do not think it is needed (at least not when using HeadFile) but I am not sure about that.

(the script:
https://raw.githubusercontent.com/wiki/apryet/Qgridder/tutorial/script_tutorial_steady.py
)

[apryet]

Right, thank you ! I will update this tutorial asap.