Add National Levee Database to PyGeoHydro

[colby-thrash]

Would you ever consider adding the USACE National Levee Database to PyGeoHydro Web services? I see there is a levee layer in the NFHL module but it seems to only contain a few of the levees from my one test area.

Thanks for creating these excellent tools!

[cheginit]

Thanks for the suggestions, I will look into it. Last year I checked their web service, and implementing it wasn't very straightforward. So, I will look into again, hopefully, it's been improved!

[cheginit]

@colby-thrash It took a while for me to get around to this.

I just added support their REST service. Can you please give it a try and let me know if it contains the data that is usually needed for common levee analyses? You can install pygeohydro from git and then just do from pygeohydro import NLD. The class's docstring has an example.

[colby-thrash]

@cheginit Awesome thanks for looking into this! Sorry it has taken me a while to get back to this as well. I installed from git and plan to take a look this week.