US Customary Units Input

[antonalleyprovo]

Summary
When creating the input file, a nice way to be able to put everything in as US units would make everything a lot easier. Right now I have to convert US to Metric just for the model to convert it back to US. So I am doing a lot of multiplications in my python code.

Additional context

[kaklise]

I think this is an easy addition to WNTR, we'd just want to make sure that the update does not cause confusion to the standard that WNTR uses SI units.

The workflow could be

1. Create a WaterNetworkModel with any units, specifying that the inpfile_units are not defined (potentially the new default)
2. Write the WaterNetworkModel to an INP file without unit conversion (using a FlowUnit with conversion factor 1)
3. Specify "Units" in the INP file (i.e., GPM, LPS)
4. Load that INP file back into WNTR to create a WaterNetworkModel in SI units

The change is easy, but would require testing and documentation.

Linking #30 for a similar feature request.

[germantrujilloe86]

hola, es posible que wntr convierta los caudales de gpm a lps?