Gwlf-e

- Add "Low-Density Open Space" to Load outputs
- Remove "Other Upland Areas" from Load outputs
- Rename "Ld_Residential" to "Ld_Open_Space" in output GMS files

- Remove `bdist_wheel` as distribution because `linux` wheels are no longer
supported by PyPI. See [PEP 513](https://www.python.org/dev/peps/pep-0513/)

- Includes major improvements by Drexel for refactoring the `CalcCN` and
associated functions to reduce computation time. Accomplished by extracting
code to a number of independent functions, vectorizing, and memoizing them.
This results in an average speedup of 75% overall.
- **BREAKING** `parser` has been renamed to `Parser`
- **BREAKING** `run` now returns a tuple instead of a single value. The first
value is a JSON of results, same as before. The second value is the internal
model `z` which could be used to modularize the GMS writing in the future, as
the JSON conversion currently done is lossy.
- `numba` is now a dependency, and must be installed prior to installing
`gwlf-e`

- Add lower threshold to GrFlow to prevent double underflow.

- Set initial default for `AdjUrbanQTotal`
- Fix nitrogen/phosphorus conc transposition
- Handle input GMS file with no land cover
- Adjust low flow sediment value calculation and test

- Updated commit history to include missing release commits (no code changes)