Make `drink` generic over runtime

[pmikolajczyk41]

Sandbox should be generic over runtime. We should also provide a few example instantiations. E.g.:

• minimal - the current one
• substrate-contracts-node - taken from substrate-contracts-node
• Aleph - taken from aleph-node

[pmikolajczyk41]

on it

[pmikolajczyk41]

for now we can't do more than #24 - both aleph and substrate-contracts-node runtimes are not publishable and thus we can't use them here (since git-dependencies would prevent us from publishing drink)