* Prefer using `IQueueSpecification` and `IExchangeSpecification` instead of `string`
For bindings, use strings for source and destination names.
Add sleep so credit is granted from RMQ (HACK)
Add minimal sleep for links to be established
* No need to have exported types and functions in `common.go`
* Simplify functions and remove `PercentCodec` type
Use `fmt.Errorf`
Update modules