refactored HebrewDate to encapsulate comparing month and date to given ones
made occassions sort alphabetically
added isPesach function to HebrewDate class
added isShabuot and isSukkot functions to HebrewDate class
added isRoshHashana, is10DaysOfTeshuba and isYomKippur functions to HebrewDate class
made test code more concise
added whitespace to tests
added isRegel and isYomTob functions to HebrewDate class
refactored HebrewDate#isPurim
encapsulated choosing between ADAR and ADAR_SHENI in HebrewDate class