2.0.0

Changed

• Replaced customFormatter logic with casts that works identical to Laravel model's cast
• nova_get_setting_value($key) is now nova_get_setting($key)
• nova_get_settings($keys = null) now accepts an array of keys that define which settings to return
• setSettingsFields($fields, $customFormatter) is now addSettingsFields($fields, $casts = [])
• Added addCasts($casts = [])