Bumping to version 15.
Bumping to version 15.

grosskur/agent,Shopify/agent,buildkite/agent,Jasperswaagman/agent,grosskur/agent,Jasperswaagman/agent,buildkite/agent,Jasperswaagman/agent,es/agent,es/agent,buildkite/agent,Shopify/agent,es/agent,Shopify/agent,grosskur/agent