Support for stack v 7.8.0

• RUM agent v5.2.1
• Java APM agent v1.17.0
• Elastic stack v7.8.0

Support for Stack v7.7.0

• Updated to support Stack v7.7.0
• Updated APM agent to 1.16.0
• Support for ECS logging and log correlation with APM
• Misc fixes to streamline the build process

Initial release

Runs with minikube, Elastic stack v7.4.0, k8s 1.16.0