fix(numpy): aliases of builtin types is deprecated

[mwtoews]

This is a re-do of #1052 for changes from #1078.

[mwtoews]

Also, FYI int is 32-bits on Windows and 64-bits on most other computers. This issue is not addressed in this PR.

[codecov]

Codecov Report

Merging #1105 (df3c87f) into develop (f3124b5) will increase coverage by 0.978%.
The diff coverage is 50.000%.

❗ Current head df3c87f differs from pull request most recent head 14a842a. Consider uploading reports for the commit 14a842a to get more accurate results

@@              Coverage Diff              @@
##           develop     #1105       +/-   ##
=============================================
+ Coverage   71.748%   72.727%   +0.978%     
=============================================
  Files          225       221        -4     
  Lines        51856     51081      -775     
=============================================
- Hits         37206     37150       -56     
+ Misses       14650     13931      -719     

Impacted Files	Coverage Δ
flopy/plot/crosssection.py	55.712% <40.000%> (ø)
flopy/plot/map.py	70.748% <50.000%> (ø)
flopy/utils/rasters.py	56.589% <100.000%> (ø)
flopy/modflow/mfswi2.py	62.461% <0.000%> (-9.847%)	⬇️
flopy/modflow/mfoc.py	91.732% <0.000%> (-2.953%)	⬇️
flopy/modflow/mfbcf.py	87.939% <0.000%> (-2.011%)	⬇️
flopy/utils/datafile.py	72.811% <0.000%> (-1.383%)	⬇️
flopy/utils/mfreadnam.py	76.642% <0.000%> (-0.730%)	⬇️
flopy/utils/flopy_io.py	75.641% <0.000%> (-0.428%)	⬇️
flopy/mt3d/mtcts.py
... and 3 more