Task (Reminder) model

Added calendar view for reminders.

Reminders can be added via button or via pressing a time on the calendar.

Reminders can be update via drag and drop or via clicking on a reminder and a modal will show.

Reminders can be deleted by clicking on a reminder and a delete button is available on the modal.

Time is stored as number now
This method can be deleted as it's been replaced by editEvent
Name should be changed, though, so editEvent = editReminderTime, to comply with the rest of the method names.