The purpose of the repository at hand is to verify credit card details. The credit card details, for a particular test case are verified using Luhn's algorithm, also known as the modulus 10 or mod 10 algorithm, is a simple checksum formula used to validate a variety of identification numbers, such as credit card numbers and IMEI numbers and CSIN. pytest is an efficient tool for performing unit testing and hence it is employed. This is present in test_cardValidator.py Go on: https://travis-ci.org and check out the instructions to run travis ci which performs unit testing for us