Introduce new Action DSL

[#82593712]

Signed-off-by: Eric Malm <emalm@pivotal.io>
Signed-off-by: Nick Wade <nwade@pivotal.io>
Make Actions required on Try and Timeout

[#82593712]

Signed-off-by: Matthew Sykes <matthew.sykes@gmail.com>
Guard against un/marshaling nil Actions

[#82593712]