Fixed building on Python 3.10

[bjrubinstein]

No description provided.

[djlampert]

Change the import statement for setuptools to combine it with the other imports rather than having two import statements in a row.

import os, sys, setuptools

[djlampert]

In the hspfmodel file, on line 54 in the proposed file, change "wdmutil" to "hspfmodel," since this is an error message for the hspfmodel constructor (you copied the text from the wdmutil constructor, I think).
print('You can pass messagepath to the wdmutil constructor.')
In the wdmutil file, on line 35 there appears to be an extraneous print statement. Please delete (unless I am wrong).