Release v0.9.27

• Add support for Ruby 3.0 endless method definitions. (#1376, #1381)
• Add existence check for README file (#1367)
• Support module_function decorator (#1365)
• Add CommonMarker markup support (-m commonmarker) (#1157, #1388)
• Fix nested array parsing (#1389)
• Add WEBrick as a runtime dependency for Ruby 3.0 support (#1400)
• Support fail_on_warning option in yard stats command (#1392)
• Better integration with Sorbet (#1401)
• Handle include mixins on complex paths (#1386)
• Fix @!scope maintaining state in lone comment blocks (#1411)
• Remove support for Travis CI