- Add support for new request and response headers, supporting flexible
versions / tagged fields
- Add List / Alter partition reassignments APIs
- Add support for varints
- Add support for compact collections (byte array, string, array)

* Hotfix: TypeError: object of type 'dict_itemiterator' has no len()

* Avoid looping over items 2x

Co-authored-by: Grabowski <chris@crawlinski.com>

* Co-authored-by: Andrew Brown <andrew.brown@shopify.com>
* Co-authored-by: Aaron Brady <aaron.brady@shopify.com>

* Add consumergroup related errors
* Add DeleteGroups to protocol.admin
* Implement delete_groups feature on KafkaAdminClient

* Add logic for inferring newer broker versions

- New Fetch / ListOffsets request / response objects
- Add new test cases to inferr code based on mentioned objects
- Add unit test to check inferred version against whatever resides in KAFKA_VERSION
- Add new kafka broker versions to integration list
- Add more kafka broker versions to travis task list
- Add support for broker version 2.5 id

* Implement PR change requests: fewer versions for travis testing, remove unused older versions for inference code, remove one minor version from known server list
Do not use newly created ACL request / responses in allowed version lists, due to flexible versions enabling in kafka actually requiring a serialization protocol header update
Revert admin client file change

This is in preparation for adding `zstd` support.

Implement methods to convert a Struct object to a pythonic object