v0.5.0

v0.4.0

Updates to support comparisons with CDR v4 code. The CDR v4 code was also based on code originally authored by Goddard, but had some minior differences.

Extract CDR-specific logic from this repository. Moved to the seaice_ecdr (https://github.com/nsidc/seaice_ecdr/)
Remove Hemisphere type. Import from pm_tb_data instead.
Remove CLI for this library. It is now the responsiblity of programs utlizing this library to define how inputs/outputs are handled. This library purely focuses on the implementation of the sea ice concentration algorithms.
Related to the above, remove code related to reading/handling ancillary files that define e.g., valid ice masks. This code was very specific to NSIDC's internal infrastructure and unpublished data. It is now the responsibility of other programs utlizing this library to provide masks, input TBs, etc.
Replace BootstrapAlgError in get_linfit with a logged warning. Use default slope and offset values instead of failing when there are less than 125 valid pixels
Separate AMSR2 and AMSRE parameter coefficient specifications.

Bootstrap: stop wrapping data computations in functions that cast data to np.float32. This was done originally to exactly match the outputs of the Fortran code provided to us by GSFC.
Replace custom linfit function used by bootstrap algorithm with numpy.polyfit.
Refactor of Bootstrap and NASA Team algorithms to allow CDR to apply weather filters and land spillover adjustments independently of the sea ice concentration calculation.
Replace fetch subpackage with usage of pm_tb_data. See the pm_tb_data repository for more information.
Bootstrap parameters:
- Begin refactoring of how parameters are defined (e.g., begin to remove concept of TiepointSet)
- DRY out duplicate paramters and make the chain of inheritance more clear (e.g., the initial BT params used by the CDR for AU_SI12 was provided by Goddard for AMSRU and adapted for our use-case (weather filter parameters updated for AU_SI12).
- Define tests that assert pre-defined initial bootstrap params are not changed. These sets of parameters should be immutable. New sets of parameters that inherit from a previous set should make it clear that they do so instead of overwriting existing values

Packaging fixup: include py.typed in built package so that other libraries (e.g., nise can run type checking against types defined in this package)