Added

• add echo example #208 (mehulgohil)
• added example for iris web framework #199 (mehulgohil)

Changed

• ESD-32688: Improve locking and blocking associated with key retrieval #225 (ewanharris)
• Replace deprecated pkg/errors in favor of Go's standard library #189 (molaga)
• Replace square/go-jose with go-jose/go-jose #188 (sergiught)
• Fail to instantiate validator when audience is an empty string #183 (sergiught)