Ubuntu: Pin to Erlang 21.3 for RabbitMQ

Signed-off-by: Jared Ledvina <jared@techsmix.net>

CHANGELOG.md

@@ -8,7 +8,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/).
 ## Changed
 - Update all package URLs to new EOL domain (@mho-CL & @jaredledvina)
 - Update README with EOL status of Sensu Core (@jaredledvina)
-- Debian: Upgrade Erlang to 21.3 for compatibility w/ rabbitmq-server (@jaredledvina)
+- Debian/Ubuntu: Upgrade Erlang to 21.3 for compatibility w/ rabbitmq-server (@jaredledvina)
 
 ## [5.4.0] - 2019-07-20
 ## Changed

vars/Ubuntu.yml

@@ -8,7 +8,7 @@ sensu_redis_service_name: redis-server
 
 
 sensu_erlang_pin_package: 'esl-erlang erlang*'
-sensu_erlang_pin_version: '1:20.3*'
+sensu_erlang_pin_version: '1:21.3*'
 sensu_rabbitmq_signing_key: https://dl.bintray.com/rabbitmq/Keys/rabbitmq-release-signing-key.asc
 sensu_rabbitmq_repo: "deb https://dl.bintray.com/rabbitmq/debian {{ ansible_distribution_release }} main"
 sensu_rabbitmq_erlang_signing_key: https://packages.erlang-solutions.com/debian/erlang_solutions.asc