Add syncing with Monarch

It is valuable because Monarch tracks transactions for lots of accounts and even couples, but it doesn't have the peer to peer splitting of transactions like SplitMyExpenses does. So if Monarch could sync with SplitMyExpenses, it would pull all expenses from Monarch, instead of by adding more accounts to SplitMyExpenses and having 2 different platforms trying to sync and have access to all the accounts, and instead SplitMyExpenses just takes the information from Monarch.