rio-pmtiles python package [#338] (#542)

Add rio-pmtiles command line tool. [#338]

This is derived from the original mapbox/rio-mbtiles implementation, with changes:

* output PMTiles only instead of MBTiles.
* Python 3.7+ only.
* remove --implementation, --image-dump, --append/--overwrite, --covers features.
* bump dependency versions.
* better progress reporting; add pyroaring. 
* update README and license texts.
* rio-pmtiles v0.0.6 on PyPI

python/pmtiles/bin/pmtiles-convert

@@ -0,0 +1,55 @@
+#!/usr/bin/env python
+
+# pmtiles to files
+import argparse
+import os
+import shutil
+
+from pmtiles.convert import mbtiles_to_pmtiles, pmtiles_to_mbtiles, pmtiles_to_dir, disk_to_pmtiles
+
+parser = argparse.ArgumentParser(
+    description="Convert between PMTiles and other archive formats."
+)
+parser.add_argument("input", help="Input .mbtiles, .pmtiles, or directory")
+parser.add_argument("output", help="Output .mbtiles, .pmtiles, or directory")
+parser.add_argument(
+    "--maxzoom", help="The maximum zoom level to include in the output. Set to 'auto' when converting from directory to use the highest zoom."
+)
+parser.add_argument(
+    "--overwrite", help="Overwrite the existing output.", action="store_true"
+)
+parser.add_argument(
+    "--scheme", help="Tiling scheme of the input directory ('ags', 'gwc', 'tms', 'zyx', 'zxy' (default))."
+)
+parser.add_argument(
+    "--format", help="Raster image format of tiles in the input directory ('png', 'jpeg', 'webp', 'avif') if not provided in the metadata.", dest="tile_format"
+)
+parser.add_argument(
+    "--verbose", help="Print progress when converting a directory to .pmtiles.", action="store_true"
+)
+args = parser.parse_args()
+
+if os.path.exists(args.output) and not args.overwrite:
+    print("Output exists, use --overwrite to overwrite the output.")
+    exit(1)
+if args.overwrite:
+    if os.path.isfile(args.output):
+        os.remove(args.output)
+    elif os.path.isdir(args.output):
+        shutil.rmtree(args.output)
+
+if args.input.endswith(".mbtiles") and args.output.endswith(".pmtiles"):
+    print("Notice: check out the new PMTiles converter at https://github.com/protomaps/go-pmtiles")
+    mbtiles_to_pmtiles(args.input, args.output, args.maxzoom)
+
+elif args.input.endswith(".pmtiles") and args.output.endswith(".mbtiles"):
+    pmtiles_to_mbtiles(args.input, args.output)
+
+elif args.input.endswith(".pmtiles"):
+    pmtiles_to_dir(args.input, args.output)
+
+elif args.output.endswith(".pmtiles"):
+    disk_to_pmtiles(args.input, args.output, args.maxzoom, scheme=args.scheme, tile_format=args.tile_format, verbose=args.verbose)
+
+else:
+    print("Conversion not implemented")