Dev Enviroment

Tools version

Dependency	Version
Solidity	0.6.8
Web3	1.2.6
openzeppelin/contracts	(https://github.com/OpenZeppelin/openzeppelin-contracts/tree/release-v2.5.0)
openzeppelin/contracts-ethereum-package	(https://github.com/OpenZeppelin/openzeppelin-contracts/tree/release-v2.4.0)
openzeppelin/upgrades	(https://github.com/OpenZeppelin/openzeppelin-sdk/tree/release/2.5/packages/lib/contracts)