Remove deprecated fields on notification endpoint response payloads

What's Changed

• Fix gpg key deletion in CI workflow by @rubenvicario in #55
• Remove deprecated fields on notification endpoint response payloads by @rubenvicario in #54

Full Changelog: 1.0.17...1.0.18

Added support for external_id

Merge pull request #39 from OneSignal/add-external-id-param

Adds `external_id` to the Notification class to be used for idempotency

Bulk release of previous versions

Includes all previous changes; restored build and release process.

Added support for email fields

Contributed by @ndarilek in Pull Request #30

Fix set include external ids

#22

1.0.11

Added include_external_user_ids