Changes in version 0.3.1 (2019-06-28)                  

  - Fixed a bug in raster_to_png() that corrupted the output in some
    cases.

                 Changes in version 0.3.0 (2019-03-10)                  

Many function name changes in preparation for CRAN submisson. These will
certainly break existing slippymath code.

I have gone with a more explicit API since I feel users will mainly use
slippymath under the hood as a dependency. Therefore it is important
they can understand the API quickly rather than type it quickly - since
they won't do that very often.

Function names changing:

  - bb_tile_extent -> bbox_tile_extent
  - bb_tile_query -> bbox_tile_query
  - bb_to_tg -> bbox_to_tile_grid
  - tg_composite -> compose_tile_grid
  - tile_bb -> tile_bbox
  - tg_bbs -> tile_grid_bboxes

                        Changes in version 0.2.0                        

  - Added a NEWS.md file to track changes to the package.
  - BREAKING CHANGE. There were mixed lat/lon lon/lat conventions. I
    have settled on the lon/lat ordering. This means the following
    functions have changed name and argument order:
      - latlon_to_tilenum -> lonlat_to_tilenum
      - tilenum_to_latlon -> tilenum_to_lonlat