Add probot/stale to the repo. (#1681)
Add probot/stale to the repo. (#1681)


OpenZeppelin/zeppelin-solidity,OpenZeppelin/zeppelin-solidity,OpenZeppelin/openzeppelin-contracts,OpenZeppelin/zep-solidity,OpenZeppelin/zep-solidity,OpenZeppelin/openzeppelin-contracts,OpenZeppelin/openzeppelin-contracts