Create calendar-based rule system

[x] Create CSV schema for calendar-based rules (break into week-based or date-based?), and processing scripts to create them
[x] Convert season_start and season_end to periods, a nested list of calendar starts and ends
[x] Filter: Run season matching on first and second slices of periods list, if not empty/null
[x] Filter: Return dict without unnecessary values

prkng / api