Simple NFT generation contract

Testing on Rinkeby:

1. Add environment variables to .env file. See hardhat.config.ts to see which env vairables are needed.
2. Deploy contract to Rinkeby using the deploy script. Note the address of the contract.
3. Supply address to claim script to claim a NFT.
4. Watch contract on Eterscan for VFR callback, and NFT minting. You should see contract emitting associated events in the events tab onf Etherscan.
5. You can also run the testMinted script to get the minted NFT traits.

TODO:

• add hardhat-deploy plugin to manage deployements
• add metadata generation script
• add metadata methods to contract