index micro-credit base data - add and borrow

[vibern0]

Dependent on micro-credit base smart-contract#133

Expected entities

// lender user data
Lender {
id (address)
amount (amount deposited)
}

// borrower user data
Borrower {
id (address)
amount (amount received)
disbursed (date of when the borrower received the amount)
repaid (amount repaid)
interest
maturity (max date to repay)
lastPayment (date of last payment)
}

// global data
MicroCredit {
borrowers (total borrowers)
amount (total borrowed)
repaid (total repaid)
inTime (total users who paid before maturity)
}