Installments stream make dueTo part of the config.json

[andyadamides]

For installments stream:

 "dueTo": utils.now().strftime("%Y-%m-%d")[:10],

Having this, in conjunction with filtering only for entries that have a last_paid_date prevents from getting all future installments for a loan account even if they exist in the database.

dueFrom is ultimately derived from the config.json:

"dueFrom": transform_datetime(self.start_date)[:10],

Could dueTo be sourced from config.json as well and last_paid_date filter to be removed?