A smart-contract allowing Ethereum to be time-vested on a continuous schedule.

There are several publicly available smart contracts allowing for ERC20 tokens (for example those given to founders during a crowdsale) to be vested over time.

However there is no alternative for vesting 'raw' Ethereum (as opposed to wrapped Ethereum).

This contract is based on open-zeppelin's (TokenVesting.sol)[https://github.com/OpenZeppelin/openzeppelin-contracts-ethereum-package/blob/master/contracts/drafts/TokenVesting.sol]