v4.0.0

What's Changed

• Update gtfs parser interface by @takohei in #81
• update submodule by @Kanahiro in #82
• refactor, lint, fix minor bug by @Kanahiro in #83
• 4.0.2 by @Kanahiro in #84
• minversion = 3.28 by @Kanahiro in #85

Full Changelog: v3.2.3...v4.0.0