v0.2.0 SNCB added

SNCB is now a supported realtime provider either through the official SNCB GTFS realtime feed or the mirror at gtfs.be.

What's Changed

• Add realtime waiting times for SNCB by @bdamokos in #42
• Add stops visible on the map in stop explorer by @bdamokos in #39
• Clean up logging by @bdamokos in #40
• If agency.txt provides timezone info use it by @bdamokos in #41

Full Changelog: v0.1.2...v0.2.0