Support emails_to_identify and phone_numbers_to_identify in identify_users

[eligordon]

Summary

The Braze /users/identify endpoint accepts three identifier types:

• aliases_to_identify — identify by user alias
• emails_to_identify — identify by email address (requires prioritization)
• phone_numbers_to_identify — identify by phone number (requires prioritization)

Previously only aliases_to_identify was supported. This PR adds support for the email and phone number identifier types, which are used to merge email-only or phone-number-only user profiles into identified users with an external_id.

Changes

• lib/braze_ruby/rest/identify_users.rb — Accept all three identifier keyword arguments and only include non-empty arrays in the POST payload
• spec/braze_ruby/rest/identify_users_spec.rb — Add specs for each identifier type, mixed types, and empty defaults
• README.md — Document email and phone number identification examples
• CHANGELOG.md — Add entry under Unreleased

Usage

# Identify by email
api.identify_users(
  emails_to_identify: [{
    external_id: 1234,
    email: "user@example.com",
    prioritization: ["unidentified", "most_recently_updated"]
  }]
)

# Identify by phone number
api.identify_users(
  phone_numbers_to_identify: [{
    external_id: 1234,
    phone: "+15555555555",
    prioritization: ["unidentified", "most_recently_updated"]
  }]
)