Bug fixes * Various issues on Windows: testing, explicit utf-8 encoding * Strings with unescaped \ declared r"aw" Other changes: * Removed support for Python 2.7, 3.5 and added for 3.9 * Travis CI is removed in favor of GitHub actions testing across all 3 major OSes (MacOS, Windows, GNU/Linux Ubuntu) * CSL test-suite progressed from 5779a8c to c3db429