Deploy on rinkeby

[fritzschoff]

I guess this issue is more for the backlog, but it would be nice to have an instance running on the rinkeby test network.

[superduck35]

Thanks @fritzschoff

FWIW - This should be as simple as adding Rinkeby deployment details (from Compound/Aave) in test-utils/constants, then adding to the migration files. Then the deployed addresses could be added to mStable-docs && mStables-subgraph.