Bump to 2.2.4 for release

[samgavinio]

/cc @zendesk/mintegrations

Description

Bump to 2.2.4 for release. Included in 2.2.4 are

• Add CRUD support of Ticket Field Options : https://github.com/zendesk/zendesk_api_client_php/pull/368
• Add sample for the create organization API: https://github.com/zendesk/zendesk_api_client_php/pull/366

Risks

• [low] Could be wrong semver