0.2: Kafka and new APIs to work with Event

On the behalf of CloudEvents community, I'm pleased to announce the 0.2 release of cloudevents/sdk-rust.

New features

• New crate cloudevents-sdk-rdkafka: Integration with https://fede1024.github.io/rust-rdkafka. Now you can easily send and receive CloudEvents to/from Kafka using rust! #60 by @pranav-bhatt
• New nice apis in cloudevents-sdk-reqwest and cloudevents-sdk-actix-web: #57 & #58 by @pranav-bhatt
• New APIs on Event to iterate through context attributes, extensions and both: #55 & #66 by @pranav-bhatt & @slinkydeveloper
• Redesigned the event builder, now it doesn't require manual parsing of url and time and it can be cloned (to use it as template): #53 by @slinkydeveloper

Improvements & bug fixes

• Improvements in docs: #51 & #71
• Now Event deserialization does not assume default values anymore (and it fails if some mandatory attributes are not there): #41

Breaking changes

• Removed hardcoded constants from specversion crate: #52
• Redesigned the event builder, now it requires importing the EventBuilder trait and returns Result on build(). It also does not assume anymore the default values: #53

For a complete changelog, look at: https://github.com/cloudevents/sdk-rust/milestone/2?closed=1

Huge thanks to all people involved in this release!