New upstream bugfix release 1.7.1, plus:

• Fix skipped tests for vectorized extensions
• Fix tests that failed on s390x because they assumed the host was little-endian (#1937719, https://github.com/Toblerity/Shapely/issues/1102)
• Install LICENSE.txt
• Add metapackage for “vectorized” extra
• Add a -doc subpackage and build the HTML documentation
• Assorted small packaging improvements

1.7.1 (2020-08-20)

• STRtree now safely implements the pickle protocol (#915).
• Documentation has been added for minimum_clearance (#875, #874).
• In STRtree.__del__() we guard against calling GEOSSTRtree_destroy when the lgeos module has already been torn down on exit (#897, #830).
• Documentation for the overlaps() method has been corrected (#920).
• Correct the test in shapely.geometry.base.BaseGeometry.empty() to eliminate memory leaks like the one reported in #745.
• Get free() not from libc but from the processes global symbols (#891), fixing a bug that manifests on OS X 10.15 and 10.16.
• Extracting substrings from complex lines has been made more correct (#848, #849).
• Splitting of complex geometries has been sped up by preparing the input geometry (#871).
• Fix bug in concatenation of function argtypes (#866).
• Improved documentation of STRtree usage (#857).
• Improved handling for empty list or list of lists in GeoJSON coordinates (#852).
• The polylabel algorithm now accounts for polygon holes (#851, #817).