v1.0.0

Initial release of the seasons package.

Includes functionality to:

• Get the current season of a date
• Get the date and time of the solstice/equinox in a month, which marks the beginning of a season
  • As a UTC datetime
  • As a Julian Day
• Get a list of all the solstices and equinoxes in a given year, which mark the beginning of a new season