Execution

Just for feedback
We need one trait for the specific loads that provides the implicits and a package object that provides access to all the api and types.

The actual load instance will inherit from ExecutionMain and will need both the main method with the job and attemptsExceeded interface and the implicits. We then usually have another object which defines the template method which will need to be able to import the API, etc. I don't want it to inherit things if we can avoid it.