VRFConsumerBase with UUPS

@frangio

I had no issues with VRFConsumerBase in my previous contract however now that i've made it upgradable i'm receiving some odd errors when compiling.

DeclarationError: Undeclared identifier.
--> contracts/Mint.sol:130:17:
|
130 | require(LINK.balanceOf(address(this)) >= fee, "Not enough LINK - fill contract with faucet");
| ^^^^

DeclarationError: Undeclared identifier.
--> contracts/Mint.sol:133:16:
|
133 | return requestRandomness(keyHash, fee);
| ^^^^^^^^^^^^^^^^^