small fix
add more methods in TransactionService
add extraDays column in Loan model
add calculateExtraDays method in Loan model
Use $this->assertAmount in every method in TransactionService
Add service_fee to loans table, set in disburseLoan
Add final_interest_rate to loans table, set in acceptBids
Add fee transactions to TransactionService
Add installment_period to loan
Add period column to loan
change installment namespace
Merge pull request #62 from SingularityGuy/feature/transaction-service

Feature/transaction service