Below Branches Should NOT Be Used

`testnet` branch

Based on main branch.

Specific tweaks:

chainId() tweak (fixed value) for different network: “testnet” 0x27.
istanbul compiler option change to constantinpole.
CREATE2 hash change of respective files.
Test cases changes to include chainId as a parameter.

`mainnet` branch

Based on testnet branch

Specific tweaks:

chainId() tweak (fixed value) for different network: “mainnet” 0x4a.
Compiler change same as testnet branch.
CREATE2 hash change of respective files.
Test cases changes same as on testnet branch.