Upgrades the AWS SDK to the same version that we're using for the repository-s3 plugin, providing
testing capabilities to override certain SDK endpoints in order to point them to localhost for testing.
Adds tests for the various credential providers.
Renames the following settings to remove the mention of `zen` in their names:
- `discovery.zen.hosts_provider` -> `discovery.seed_providers`
- `discovery.zen.ping.unicast.concurrent_connects` -> `discovery.seed_resolver.max_concurrent_resolvers`
- `discovery.zen.ping.unicast.hosts.resolve_timeout` -> `discovery.seed_resolver.timeout`
- `discovery.zen.ping.unicast.hosts` -> `discovery.seed_addresses`
This commit adds a new QA sub project to the discovery-ec2 plugin.
This project uses a fixture to test the plugin using a multi-node cluster.
Once all nodes are started, the nodes transport addresses are written
in a file that is later read by the fixture.