Add hotel room booking smart contract

[nabroleonx]

Is your feature request related to a problem? Please describe.

This is a simple hotel room booking smart contract where one can rent a hotel room using the example Solidity smart contract for a hotel room booking. If a room is unoccupied, it permits someone to make a payment for it. The owner receives the payments after the contract has been paid. After the money is received, this smart contract can be modified to unlock the door or give out a key code.

[nabroleonx]

If this isn't already done, assign it to me and I can send pull request.