It is impossible to use quickcheck with no-std builds

[abizjak]

Bug Description

concordium-quickcheck enables the std feature of concordium-std.

This in turn means it is impossible to do a no-std build as long as quickcheck is used.

This is partly caused by the fact that cargo concordium test as of now builds the contract using normal dependencies for testing, which in turn means that quickcheck must be normal dependency.

This issue is reported in Concordium/concordium-smart-contract-tools#21

This makes it challenging to use the quickcheck feature since no-std builds have significant advantages for size of the resulting binary.