0.3.0rc1

Pre-release for testing.

• Delayed (time-window) smart charging: set_delayed_charging() and set_delayed_charging_schedule().
• Price-based (dynamic-tariff) smart charging: set_price_based_charging() and set_price_based_charging_settings().
• boost() to charge now, overriding whichever smart charging profile (delayed or price-based) is active.
• Weekday IntEnum (isoweekday-numbered); days can also be given as numbers or names.