Problem with the package "github.com/CovenantSQL/CovenantSQL/client"

[LaraSchvartzman]

Hi, I'm trying to use the CookieScanner so I succesfully got all the packages required, except for this one: https://github.com/CovenantSQL/CovenantSQL/tree/develop/client
When I type go get "github.com/CovenantSQL/CovenantSQL/client" and after that go get "github.com/CovenantSQL/CovenantSQL/cmd/cql" I get the same terminal prompt
go/src/github.com/CovenantSQL/CovenantSQL/blockproducer/interfaces/transaction_wrapper.go:169:20: decodeDriver.TryDecodeAsNil undefined (type codec.genHelperDecDriver has no field or method TryDecodeAsNil)
Afterwards, when importing either package I get the error:
../../go/src/github.com/CovenantSQL/CovenantSQL/blockproducer/interfaces/transaction_wrapper.go:169:20: decodeDriver.TryDecodeAsNil undefined (type codec.genHelperDecDriver has no field or method TryDecodeAsNil)
This happens for WriteArrayElem, ReadArrayElem and TryDecodeAsNil
How can I fix this? Thanks!