pyshp version lock limits usage with cartopy

[gcoyle83]

Issue description

This may be a very edge case issue for you all, and I want to lead with a thanks for the work on this library. That said, I tend to use cartopy to develop maps for displaying geospatial data. Cartopy requires pyshp>=2.3, while swmmio appears to be locked to pyshp==2.1.0, which is going on six years old. Understanding your core objective is maintaining your own library, not compatibility with arbitrary others, is it a big ask to update to the latest pyshp to resolve this?

To reproduce

Build env with basic dependencies:

name: test_env
channels:
 - conda-forge
dependencies:
 - python==3.11 
 - cartopy 
 - jupyter 
 - matplotlib>=3.6 
 - pip 
 - pyproj>=3.3.1 
 - pyshp>=2.3 
 - shapely>=1.8 
 - pip:
    - pyswmm[swmm5.2.3]

Then run example from cartopy docs:

import cartopy.crs as ccrs
import matplotlib.pyplot as plt
ax = plt.axes(projection=ccrs.PlateCarree())
ax.coastlines()
plt.show()

This should work. Add swmmio to pip installs, and then it will not work, throwing a ShapefileException error due to pyshp version lock.

[aerispaha]

@gcoyle83 thanks for raising this! I don't recall any reason why we're locked on an old version of pyshp. I can run some tests to see if this causes any problems. If it doesn't, I think we can make this change in the next release.

[aerispaha]

@gcoyle83, seems like upgrading pyshp is totally doable. I've got this ready in #236

[gcoyle83]

Thanks for the quick response to this!