Prepare a data frame for RFM

A function to process the input data frame of transcation records so that the data frame can be ready for RFM scoring.

	A.Remove the duplicate records with the same customer ID
	B.Find the most recent date for each ID and calculate the days to the endDate, to get the Recency data
	C.Calculate the quantity of translations of a customer, to get the Frequency data
	D.Sum the amount of money a customer spent and divide it by Frequency, to get the average amount per transaction, that is the Monetary data.