• Add GitHub build actions for project
• Add project URLs in setup.py (thanks to Steve Piercy)
• Update README links (thanks to Steve Piercy)
• Fix handling of README in setup.py (encoding fun in 3.5, 3.6 and pypy3)
• Fix README links (thanks to Chris Barker)
• Add Python 3.9 to test matrix (thanks to Luciano Mammino)
• Add type hints (thanks to Brett Cannon)
• Derive ParseError from ValueError (thanks to Lex Robinson)