4th stable release

• MIT License added.

3rd stable release

• In Staking.sol file, ^0.8.0 replaced with ^0.8.5 in this commit

2nd stable release

• Added upgrade script for staking contract,
• Showing transaction hash in deployment script,
• Added an unit test function in Ownable

1st stable version created

• Successfully compiled
• Unit tests running successfully
• Deployable to localhost, Rinkeby testnet, Ethereum mainnet