Race Timing System: Run the included demonstration

Run the included demonstration

From this extracted folder:

python3 -m unittest discover -p test_timing.py
python3 zebra_timing.py --db demo.sqlite3 tags tags.csv
python3 zebra_timing.py --db demo.sqlite3 replay sample_reads.jsonl --reader fx9600-main --race open-5k --race lap-race
python3 zebra_timing.py --db demo.sqlite3 status
python3 zebra_timing.py --db demo.sqlite3 export demo_results.csv --basis gun

Expected: bib 104 finishes in 61 seconds gun / 60 seconds chip. Bib 105 completes two laps in 82 seconds gun / 80 seconds chip. Replaying the file again adds zero reads. These are simulated events, not a hardware test.