V0.4.0

Notable changes:

• Kubernetes dependencies have been upgraded to version 1.14
• Optional ConfigMaps and Secrets are now correctly handled across all references in Deployments, DaemonSets and StatefulSets

Full changes since V0.3.0:

• Update Controller runtime to v0.2.0-beta.4 (#60, @JoelSpeed)
• Use image entrypoint for manager container definition (#57, @zerok)
• Allow optional ConfigMap / Secrets (#61, @theobarberbany)

Thanks to all who contributed to this release!