slopes 2.0.0

• Migrated from the deprecated raster package to terra (closes #60). terra is now a hard dependency (Imports); raster is no longer required or suggested.
• elevation_extract(), slope_raster(), and elevation_add() now always use terra. The terra = argument is deprecated (with a message) and ignored.
• elevation_get() now always returns a SpatRaster. The output_format = argument is deprecated and ignored.
• slope_matrix_to_raster() and slope_xyz_simple() now work with SpatRaster objects. Legacy Raster* objects are accepted with an automatic conversion message for backwards compatibility.
• The bundled dataset has been renamed from dem_lisbon_raster to dem_lisbon and is now a SpatRaster object (was a RasterLayer).
• Fixed CRAN --run-donttest failure: the ceramic/Mapbox-dependent example in elevation_add() is now wrapped in \dontrun{} instead of \donttest{} (closes #72).
• Fixed slopes_palette() hardcoded testing logic, allowing it to correctly return any number of requested colors for the “Green-Brown” palette.
• Substantially improved overall package test coverage (from ~59% to over 84%) by adding test wrappers for plot functions and matrix conversion utilities.

slopes 1.0.1

• Package source code now hosted at https://github.com/ropensci/slopes
• New documentation section showing how directed routes work: https://docs.ropensci.org/slopes/articles/slopes.html#splitting-the-network

slopes 1.0.0

• We have submitted and responded to all comments to rOpenSci review.
  
• Many changes, including breaking changes to function names.
  
• Added a NEWS.md file to track changes to the package.

slopes 0.0.1

• Initial version of the package on GitHub.